Is there a compilation anywhere that details the changes year to year on R5's through RZ models?
I started with a set of R5 cases and of course they don't have grooves for Main oil seals and not bearing retainer plate. Then I got a set of RD350 cases and RD400 cases with subtle changes, so then I looked at a set of TZ cases which are almost the same but very different in other ways. For example the kickstarter gear spring mounts like an RZ/LC but everything else is more like an RD. And tehTZ never had a kickstarter so why?
LC cases seem to have wider cases that RDs combined with cylinder stud spacing the same as Air cooled models, so they appear to be half way between RD and RZ. The water pump shaft boss and water pipe hole are like an RZ as well.
RZ appears to be the same as an LC but with new cylinder mounting studs and mouths.
Is there a reference site with all these details and more?
Yeah, fun to see the evolution of the Yamaha 2T twin.
Next in line after RZ was a few minor changes for the Banshee and then big changes for the 1KT TZR when they moved to case induction.
Fun stuff.
But it looks like no one has documented the changes/history.
I was mocking up a banshee side cover to a set of RD350 and RD400 crankcases and that's where I started to see more changes than I had noticed when I was rebuilding TZs
I did this with cylinder porting layouts from R5 to RZ, and also TZ, on my website also TZ porting arrangement pics and more in depth cyl development history on the 125, 200 and 250 because 90 percent of what I've done/do is RD/TZ porting. That's on www.erlenbachracing.co
Let's compile a kind of a general engine's differences in this thread then sumrize it and put it in the tech library here for quick reference that would be a nice resource. Ed
Alright i'll start. When I think about RD's and TZ's to give my RD/TZ history some reference to the work I've done with them I've always considered the time span from the 1970 R5 to the 1990 reverse cylinder TZ250 because the R5/DS7 was the first Yamaha to have the horizontally split cases with 4 transfer port cylinder base case layout (2 on each side with a 5th boost port added in the RD series).
This means RD cylinders will bolt directly onto the R5/DS7 cases.
BUT the R5/DS7 only had 5 speeds though it's super easy to swap it all out for an RD 6speed setup (gotta love Yamahas parts interchangeability!)
A SLIGHT variant of these cases was used by the TZ250/350 up until 1980, if fact when TZ racers broke earl TZ cases it was uber common to replace them with RD cases.
I stop at the 1990 reverse cylinder TZ250 because it was the last of the Yamaha parallel twins.. Ed
o.k. here's some more..
This is a direct quote from the Aircooled RD Club Forum, I read it years ago and went back and dug it up, I've never seen a solid mounted RD400 but there is tale..
"The RD400 originally arrived in the US and australia with a solidly mounted engine hence the un-jointed pipes
this was going to be the production model until the bike was tested in europe and slated for its heavy vibration caused by the longer stroke
this then led to a series of stop gap measures to help this including
a rear rubber mount for the pipes and indeed the jointed type seen on the 250 before eventually settling on the engine mounts and rubber joints as seen on the final 400 model
There were some UK machines around during the early days with variations of either of the above although i know one for certain that had later pipes fitted in 1977
and around 150-200 RD400 "C" models with the solid pipes as pictured above"
Alright some ramblings from my memory..
On RD400 cases I've seen slight differences in the castings, the earliest had a little less material around the cylinder base gasket area at the rear and more ribbing around the right main bearing for sure (and right transmission mainshaft bearing if memory serves me correctly) in later cases.
Starting with Daytona in the US and later UK cases used a different kickstarter mechanism. Daytona I know would take the earlier kickstart mechanism, I "was told' back then that the gear on the "Daytona style" kickstart mechanism which on this new design was not constantly engaged with the idler gear in racing had slid over and engaged on some so common practice was to retrofit the old system when using "Daytona' cases. I did have one customer that would not take no for an answer so I used a throttle slide return spring to keep the kickstart gear positively disengaged when not in use. One drawback with the "Daytona" style kickstart mechanism was that it kicked over more slowly as well.
While the rest of the world got electronic ignition in 79/80 we didn't here in the states..
The Daytona did get a new crankshaft without the dreaded lead weights but improper heat treating it's believe causes them to snap the center section under racing conditions..
All electronic ignition bikes got a new LC/RZ style larger taper on the ignition end of their crankshafts.
LC's went to the now well know RZ/Banshee style crankshaft but the LC's still has a 16mm wide big end bearing but with large big end and wrist pin bearing diameters.
An LC crankshaft will fit in Aircooled RD cases, A RZ/Banshee crankshaft is a mm too wide.
I believe Joe Spooner's TZ375 is using an aircooled RD bottom case with an LC top case and said it bolts right on.
The RD/LC/TZ/RZ/Bamshee right side covers all have the same bolt pattern but the RD400 has one more bolt provision in the case at the front but it doesn't mean you can use the other side covers on it as I've installed LC and TZ side covers on all the aircooled RD's (250/350/400).
^^^^^you are partially right on my engine Ed, the LC and AC cases will bolt together (kind of) but not enough to use them that way. They fit together well enough so that I could use the AC bottom case for alignment in the frame so that I could build motor mounts for the LC bottom end that I used for my TZ375 motor because the LC motor is mounted in the frame exactly like the RZ/Banshee motors. I am using an RD400 left side cover on my engine as well, everything lined up perfectly and the 400 cover can be made to look just like a TZ side cover.
Any TD3, TR3 and TZ250, 350, 700 and 750 top end will drop straigh on to any R5, DS7, RD250 or RD350 set of crankcases but the studs may be the wrong length. I have a list of stud lengths here somewhere because I have gone through this a few times already.
I have bought and/or worked on TZ and TR/TD motors with replacement unstamped cases as well as RD cases, but RD cases have to be machined for the rubber mounts on the front and they have to be machined to take the pair of C clips for the center bearings and lab seal.
A Banshee or RZ clutch cover will almost fit onto an RD set of cases but the 'Shee and RZ have a liittle more metal in two places. The RZ/Shee water pump will not work on an RD set of cases because they are missing the rear water pipe passage and the boss to support the pump shaft.
Banshee/RZ and LC all have a longer right crank snout to take the water pump drive gear. That gear cannot be fitted to an RD crank unless the end is drilled and tapped and the drive gears are replaced with straight cut gears.
There are some differences with front mounting screws for a shee/RZ and I think that some TZ and RD400 cases are similar to the Shee/RZ, but I need to check.
RZ cranks are wider across each pair than RD's and will not fit in the crankcases, but I would think that RD cases could easily be machined to take a wider RZ crank but that might cause a primary gear misalignment - I have not checked that possibility.
An RD clutch cover can be cut down around the oil pump and a TZ water pump will be driven through the original oil pump drive shaft hole, but that requires an adapter to fit under the pump.
R5/DS7 did not have teh gearbox input shaft bearing retainer and the grooves to locate crank oil seals were added with the RD series.
LC and RZ have a similar kickstarter arrangement. On the RZ ( I don't have an LC to measure) the inner end of the short kickstarter shaft is a smaller diameter, so either the cases need to be bushed or a sleeve pressed onto the shaft. The shaft is longer than an Air cooled motor which is fine if you use an RZ clutch cover.
On an RD, the kickstarter idler gear is a pair of gears. One engages with the kickstarter and the other with the small gear on the back of the clutch. on an LC or RZ there is only one dished gear which engages with both the clutch gear and the kickstarter bendix. To complicate matters further the small spring around that kickstarter gear is also different on an LC and RZ compared to an RD and I suspect that design change came with the Daytona.
BTW, TZ and RD crankcases have a few other subtle differences related to how oil drains between the transmission and primary drive.
LC and RZ cranks and shifts assemblies are also not the same. The cranks are different widths as the shift drums are different lengths. Very slight but there. RZ/LC studs are different pattern. They are all very similar motors from the R5 through the TZR when it comes to rebuilding.
you =can= use an lc crank in aircooled cases as mentioned, but also as mentioned, you need to mod the end of the crank, OR, as i have done, 'doghouse' the RH cover to take the longer crank. (no oil pump can be used after this mod) the LC crank also allows for a large taper cdi to be used, and yes, an rz or lc cdi will then bolt right on to aircooled cases. you will need to clearance the LH cover to accommodate the cdi pickup.
:twocents:
and the keyway on a Daytona crank is 90 degrees off the RD-LC and RZ cranks
Quote from: motodreams on July 08, 2019, 09:10:01 AM
LC and RZ cranks and shifts assemblies are also not the same. The cranks are different widths as the shift drums are different lengths. Very slight but there. RZ/LC studs are different pattern. They are all very similar motors from the R5 through the TZR when it comes to rebuilding.
And transmission shafts are also longer on an RZ/Banshee than air cooled models plus they run a three shift forks and not 4.
This is fun.
-Unlike the RZ/Banshee's LC's still had the clutch pushrod that went all the way through and out the left side of the cases to a clutch actuator in the left side cover.
-The LC's use the same part number kickstarter mech as the RZ/Banshee
-Yes the LC kickstart shaft is considerably longer than RD's, twice to use an LC side cover I grafted two early style RD kickstart shafts together to extend them I believe 16mm
-The LC used a three shift fork trans like the RZ but I don't know if the trans was the same as the RZ?
-I didn't know an RZ/Banshee right side cover wouldn't work on an RD.. I'd seen a TZ Dryclutch cover on an RZ or 2 and they are a straight bolt on for an RD as is the LC cover so I assumed..huh
-guys have used RZ cranks in RD's but it takes a little machining
-other guys have used the wider RZ rods in RD's by machining .5mm off the inside of each crankweb.
-The early TZ's used the double kickstart idler gear to drive their tach but the gear ran on a needle bearing.
-Since Daytona and later RD's used the single gear kickstart idler gear they used a longer tach drive shaft and internal gear ratio in the case right before the cable, also a smaller tach drive nylon gear.
-TZ250 and 350 had different primary gear ratios than the RD's so they used 2 different nylon tach drive gears (and 2 different water pump drive gears)
-You can run RZ/Banshee primaries on an RD I've done it a number of times
-The Daytona and later left side covers had a provision for the electronic ignition pickup
-The Daytona had thinner primary gears
-The Daytona 5th and 6th gears had thinner engagement dogs which made them easier to shift into these gears but no good for racing..
-The Daytona and later used a different shift mechanism ratio
-cool i never noticed about the keyway
Hmm let me think some more
Banshee side cover fits almost all the way around but is just a little thin in two places. A little JB weld or Devcon is fine. You could probably get away without that, but I wanted to be safe. That allows a Banshee/RZ clutch assembly to be used with stock or straight cut gears and also allows a lock up clutch to be slipped under the cover.
To use a TZ waterpump instead an an oil pump, use the RD oil pump gear IIRC. Or use an electric waterpump - cheaper and can be switched on only when needed using a thermo switch in a 750 head or tap one in for a 250 or 350 head.
Has anyone tried to get TZ port timing out of an RD400? Long stroke and long rods make life more difficult, but looks like it may be possible with a 6mm lift plate and corresponding amount off the top of the barrels. It will never come close to matching a CPI Cheetah for port time area but might be a little closer.
A set of TZ750D 6 or or OW31 barrels or even 3G3 with reed boxes, might be closer still but not close to what a Cheeta can create.
Probably the thing that has given me the most enjoyment over the years working on RD's is that on an average guys budget with hard work (lots of time, lots of thought, lots of more thought and lots of more hard work yes..) and the patient and persistent application of good science (and yes more hard work..) these bikes can very often just honestly do "more than their supposed to be able to do".... You gotta love em, don't let anybody tell you their not the race bred descendents of the RD56 like their racing cousins like I tell guys when their on the pipe they don't know their not TZ's!!! Gotta love em, all that rolled up in aircoooled simplicity.. No RD's are not CPI cylindered RZ/Banshee megabuck motors but dam can they perform with a lot of hard work and good science.. Ed
but dam can they perform with a lot of hard work and good science.. Ed
... I've noticed that ;D
Quote from: EE on July 09, 2019, 05:22:35 PM
Probably the thing that has given me the most enjoyment over the years working on RD's is that on an average guys budget with hard work (lots of time, lots of thought, lots of more thought and lots of more hard work yes..) and the patient and persistent application of good science (and yes more hard work..) these bikes can very often just honestly do "more than their supposed to be able to do".... You gotta love em, don't let anybody tell you their not the race bred descendents of the RD56 like their racing cousins like I tell guys when their on the pipe they don't know their not TZ's!!! Gotta love em, all that rolled up in aircoooled simplicity.. No RD's are not CPI cylindered RZ/Banshee megabuck motors but dam can they perform with a lot of hard work and good science.. Ed
Agree 100% and while we all think we'd love to ride a 250 pound 180HP street bike, it ain't happening anytime soon anywhere near here.
The last RD I worked on was an early model 350 with stock carbs and it made 52hp while cool and that was wild enough and tons of fun. And people can get more out of them than that - especially 400's.
For what they are and what they were designed to be, way more fun that they have any right to be.
Are there any side covers that are interchangeable with the RD350LC? Maybe a RD400? I am still looking for a solution for the hard to find clutch actuator mechanism missing on my LC...
Quote from: motodreams on July 11, 2019, 04:22:01 PM
Are there any side covers that are interchangeable with the RD350LC? Maybe a RD400? I am still looking for a solution for the hard to find clutch actuator mechanism missing on my LC...
https://www.ebay.co.uk/itm/Yamaha-Rd350lc-Left-Engine-Cover/283444525924?hash=item41fe9c3b64:g:~okAAOSwoQpcqnqA
Joe said he used an RD400 left side cover on his LC350 cases on his TZ375 project. Ed
Quote from: motodreams on July 11, 2019, 04:22:01 PM
Are there any side covers that are interchangeable with the RD350LC? Maybe a RD400? I am still looking for a solution for the hard to find clutch actuator mechanism missing on my LC...
Yes, RD400 fits perfectly, you just have to make some room for the electronic ignition trigger for the LC. Ill take a pic of mine and post it in a bit.
And some more info:
-1962 The RD56 Yamahas first World Grand Prix Champion winner (56x50 rotary valve 250)
-1967 The YR1 Yamahas first horizontally split parallel twin (61x61 350 / 2 transfer port cylinders)
-DS7 / TD3 250
-R5 / TR3 350
-DS7 / R5 1970-72
-TA250 early 1973 aircooled TD3/TZ hybrid
-An interesting point: The some of the "works" TR3 engines from 1972 sported 6 transfer ports, like an F/G model 350.
-Early TZ's based on "RD" cases 1973-1980 Piston ported monoblock cylinders
-The TZ250 G in a last ditch effort to get ever last hp out of the "RD" based case engines ran an intake so big it became know as the piston eater..
-In 1981Yamaha totally redesigned the TZ250 engine. Having reached the limit of intake port size in the G, the H models crankshaft rotation was run backwards to put piston thrust on the cylinder wall opposite the intake allowing further increases in intake port size. The cylinders were now individual but still piston port. Also new was Yamaha's exhaust power valve system which in it's infancy was having teething problems.
-In 1985 Yamaha again Redesigned the TZ250 engine. 1985-1987. Switching for the first time to case reed induction allowing for much needed transfer area (2 new boost ports were the intake once was) creating needed bottom end & thereby also a wider powerband. BUT 1985's reedcages were to small and were quickly enlarged.
-In 1988 through 90 in a last ditch effort to get every last hp out of the parallel twin design Yamaha reversed the cylinders & tilted them forward to 60deg putting the carbs in front & the pipes coming straight out the back under the seat.
Quote from: Jspooner on July 11, 2019, 04:50:08 PM
Quote from: motodreams on July 11, 2019, 04:22:01 PM
Are there any side covers that are interchangeable with the RD350LC? Maybe a RD400? I am still looking for a solution for the hard to find clutch actuator mechanism missing on my LC...
Yes, RD400 fits perfectly, you just have to make some room for the electronic ignition trigger for the LC. Ill take a pic of mine and post it in a bit.
Awesome. Thanks JSpooner!
Those clear float bowls are neat.
ok I started compiling/summarizing it all... As a RD/TZ motorcycle and automotive engine builder and tuner knowing the evolution and progression of what your working on is invaluable and it's realllyyyy nice when guys put it in one place to be easily found like this, that's why my website is still up just like this thread and this forum so that others don't have to spend all those insanely long hours finding this stuff out... it's a benefit to every RD/LC/TZ/RZ nut out there when we do things like this so add in anything else you guys can think of. I reached out to an old TZ friend that knows more than I've forgotten to see what he can add and when were done i'll see what the aircooled RD club can add.
History and differences between RD250,350,400, 73-80 TZ, LC, and RZ engines
(from the 1970 DS7/R5 to the 1990 reverse cylinder TZ250) (Note: for ease of reference I refer to 73-80 TZ's which share the same cases the RD's used as "early TZ's")
-1962 The RD56 Yamahas first World Grand Prix Champion winner (56x50 rotary valve 250)
-1967 The YR1 Yamahas first horizontally split parallel twin (61x61 350 / 2 tranfer piston port cylinders)
-1970-1972 DS7/R5 start of the 4 transfer port cyl base/cases that form the basis for the RD and early TZ series
-DS7 / TD3 250
-R5 / TR3 350
-TA250 early 1973 aircooled TD3/TZ hybrid
-An interesting point: The some of the "works" TR3 engines from 1972 sported 6 transfer ports, like an F/G model 350.
-Early TZ's based on "RD" cases 1973-1980 Piston ported monoblock cylinders
-The TZ250 G in a last ditch effort to get ever last hp out of the "RD" based case engines ran an intake so big it became know as the piston eater..
-In 1981Yamaha totally redesigned the TZ250 engine. Having reached the limit of intake port size in the G, the H models crankshaft rotation was run backwards to put piston thrust on the cylinder wall opposite the intake allowing further increases in intake port size. The cylinders were now individual but still piston port. Also new was Yamaha's exhaust power valve system which in it's infancy was having teething problems.
-In 1985 Yamaha again Redesigned the TZ250 engine. 1985-1987. Switching for the first time to case reed induction allowing for much needed transfer area (2 new boost ports were the intake once was) creating needed bottom end & thereby also a wider powerband. BUT 1985's reedcages were to small and were quickly enlarged.
-In 1988 through 90 in a last ditch effort to get every last hp out of the parallel twin design Yamaha reversed the cylinders & tilted them forward to 60deg putting the carbs in front & the pipes coming straight out the back under the seat.
-Because the R5/DS7 was the first Yamaha to have the 4 transfer port cylinder base case layout (2 on each side with a 5th boost port added in the RD series) RD, LC and early TZ cylinders will bolt directly onto the R5/DS7/RD and LC cases.
-though you do need to use the correct cylinder stud lengths (Teazer)
-BUT the R5/DS7 only had a 5 speed though it's super easy to swap out the gears, shift forks and shift drum for an RD 6 speed setup (gotta love Yamahas parts interchangeability!)
-TZ cases were a separate casting than RD cases yes a very slight variant but still a separate casting, so close though in fact when TZ racers broke early TZ cases it was super common to replace them with RD cases.
-TZ cases differ from RD cases in that:
the front engine mounts are rubber mounted,
There are grooves to locate the TZ crankshaft cut into the crankshaft inner bearing area to locate the crankshaft there instead of from the primary side bearing because the TZ's used a different crankshaft (that will interchange if you cut the grooves in RD cases) that used Roller bearing mains on the outer ends.
-There is an oil passage below the shift drum not "drilled" on TZ cases between the transmission and primary gear sections of the case and the kickstarter boss has a plug in it (Yamaha part number 90338-17016 BH) (Teazer)
The oil drain is in the middle of TZ cases but offset one the RD cases. Rd crank bearing surfaces normally have a cast in steel insert and the TZ cases normally don't. BH
so TZ cases were more than just RD cases machined for front engine mounts.
- Early TZ's had a different transmission, though it would drop right in RD cases it has a VERY tall first gear and much closer gear ratio with a longer mainshaft to allow for the TZ dry clutch.
-The TZ dry clutch if combined with the TZ transmission or an RD transmission with a special mainshaft will bolt directly into an RD
-A TZ dry clutch with a special mainshaft will bolt directly on to an LC
A TZ dry clutch (with a special mainshaft) and slight modification for gasket sealing to the cases will bolt onto an RZ.
-DS7/R5 cases had no grooves in the crankshaft seal area to secure the seal as everything RD and later does. And they did not have the mainshaft clutch side bearing retainer behind the clutch.
-According to the aircooled RD club early RD400's had solid mounted engine mounts!
-RD400 cases have slight differences in the castings, the earliest had a little less material around the cylinder base gasket area at the rear and more ribbing around the right main bearing for sure (and right transmission mainshaft bearing if memory serves me correctly) in later cases.
-Starting with Daytona in the US and later UK cases used a different kickstarter mechanism. Daytona could use either kickstart mechanism, I "was told' back then that the gear on the "Daytona style" kickstart mechanism which on this new design was not constantly engaged with the idler gear like the earlier mechanism is in racing had slid over and engaged on some so common practice was to retrofit the old system when using "Daytona' cases. I did have one customer that would not take no for an answer so I used a throttle slide return spring to keep the kickstart gear positively disengaged when not in use. One drawback with the "Daytona" style kickstart mechanism was that it kicked over more slowly as well. This style also used a "single" offset idler/tach drive gear instead of the 2 gears pressed together of the earlier style since it drove the tach earlyTZ's used this gear also but ran it with a neeedle bearing. Later RZ's used the "single" gear but added a bushing to it.
-Since Daytona and later RD's used the single gear kickstart idler gear they used a longer tach drive shaft and internal gear ratio in the case right before the cable, also a smaller tach drive nylon gear
-TZ250 and 350 had different primary gear ratios than the RD's so they used 2 different nylon tach drive gears (and 2 different water pump drive gears)
-While the rest of the world got electronic ignition in 79/80 we didn't here in the states..
-The Daytona, later UK (and later RD250) did get a new crankshaft without the dreaded lead weights but improper heat treating it's believe causes them to snap the center section under racing conditions..
-All electronic ignition bikes got a new LC/RZ style larger taper on the ignition end of their crankshafts.
-LC's went to the now well know RZ/Banshee style crankshaft but the LC's still has a 16mm wide big end bearing but with large big end and wrist pin bearing diameters.
-An LC crankshaft will fit in Aircooled RD cases, A RZ/Banshee crankshaft is a mm too wide.
-you can use an lc crank in aircooled cases, but you need to mod the end of the crank, OR 'doghouse' the RH cover to take the longer crank. (no oil pump can be used after this mod) the LC crank also allows for a large taper cdi to be used, and yes, an rz or lc cdi will then bolt right on to aircooled cases. you will need to clearance the LH cover to accommodate the cdi pickup.
-The keyway on a Daytona crank is 90 degrees off the RD-LC and RZ cranks
-RZ cylinders while the would work on RD case have a much different cylinder base stud pattern, but the cylinder center to center spacing and heights are the same as a RD and LC 350 they will "slip in" they just won't bolt up
-The RZ right side cover/water pump will not work on an RD set of cases because they are missing the rear water pipe passage and the boss to support the pump shaft.
- RZ and LC have a longer right crank snout to take the water pump drive gear.
-RZ cranks "can" work in RD's but it takes a little machining
-Others have used the wider RZ rods in RD's on RD cranks by machining .5mm off the inside of each crankweb.
-An RZ clutch cover will almost fit onto an RD set of cases but the RZ have a little more metal in two places. Teazer
-An RD clutch cover can be cut down around the oil pump and a TZ water pump will be driven through the original oil pump drive shaft hole, but that requires an adapter to fit under the pump.
-LC and RZ use the same kickstarter arrangement. Similar to the Daytona and later UK RD's On the RZ/LC the inner end of the short kickstarter shaft is a smaller diameter, so either the cases need to be bushed or a sleeve pressed onto the shaft. The shaft is longer than an Air cooled motor which is fine if you use an RZ clutch cover.
-The RZ/LC kickstart shaft is considerably longer than RD's, twice to use an LC side cover I grafted two early style RD kickstart shafts together to extend them I believe 16mm
-LC and RZ transmissions use three shift forks and not 4
-Unlike the RZ, LC's still had the clutch pushrod that went all the way through and out the left side of the cases to a clutch actuator in the left side cover.
-You can run RZ/Banshee primaries on an RD I've done it a number of times
-The Daytona and later left side covers had a provision for the electronic ignition pickup
-The Daytona had thinner primary gears
-The Daytona 5th and 6th gears had thinner engagement dogs which made them easier to shift into these gears but no good for racing..
-The Daytona and later used a different shift mechanism ratio
-76-78 US RD400's had a small cutout at the bottom of the skirt on the exhaust side for emissions reasons that actually let ex gasses into the crankcase at TDC! the Daytona did not have this cutout because it used external exhaust butterfly valves between the cylinders and exhaust pipes for emissions reasons so the trick was to use Daytona pistons in all the 64mm bore RD's at least until RZ pistons came out.
-76-78 US Rd400's also came with an small exhaust bleed port from the roof of the exhaust port tunnel to approximately 10mm above the exhaust port, in performance applications it's standard practice to plug and weld these closed.
-All year RD350's in the US had Dykes ring pistons (not good for racing...)
- An RD400 left side cover will fit an LC perfectly, you just have to make some room for the electronic ignition trigger for the LC
5Port in the UK sent these differences he's seen between US and UK 250/350/400's
Here are some more engine model differences from European viewpoint:
R5/DS7 Cases sometimes do have the shallow recess for the early RD type crankseals. No idea when that changed, just can be seen on some cases.
RD250/350. Euro 351/352 models have a blocked 6th gear (different pawl plate in selector segment pins). Different sprockets to raise final drive ratio.
RD250/350B. Euro 521/522 models have 521 Model carbs, cylinderheads, gearbox and exhausts. The gearbox has all 6 speeds available and has the same ratio's of the later 250/400 with overall closer ratio's and revised final drive ratio.
RD250/400C/D. Euro 1A2 (250) and 1A3 (400). Similar to 1A1. Gearbox shafts have later type splines. Cylinderheads are marked 1A0 (250) and 1A3 (400), different casting to 1A1.
RD250/400E. 2R8/2R9. "TZ" style crank with no lead weights and slotted rods. Revised cylinders, porting and CR. Revised 400 pistons without front cut-out in skirt. CDI ignition. Revised LHS case cover with bulge over CDI pick-up coil. Gearbox and shifter changes. Narrow primary gears. Revised carbs and small X-over tube on 400. Revised 2R8/2R9 big-bore downpipes and silencers. 5Port
-Banshees had different transmission gear ratios than the RZ most everything else interchanges
RD250/350/400 Performance Parts Upgrades
RZ350 or Banshee pistons are a far superior piston than the stock pistons.
Of the cast pistons OEM are arguably the best, then Vertex, then Pro-X
Of the forged pistons Wossner, then Wiseco
The center tab at the bottom of these pistons must be removed thought (very easy),
And Vertex must be trimmed a bit if used in an RD400.
For Racing Bigbore Topends (66mm and up)
1980 IT/DT 175 pistons or Yamaha Blaster Pistons. Either piston is 5-6mm shorter than stock and requires machining the top & bottom of the cylinder to compensate for the height. The blaster pistons also have a 10deg piston dome instead of the RD/RZ/IT/DT 15deg so it does require reccutting the cylinder heads (but if yourdoing a bigbore you need to recutt the cylinder heads anyway)
Sleeving these cylinders is not ideal because of the decreased heat dissipation from the pressed in replacement sleeve and the fact that the thickness of a replacement sleeve cuts into the already limited transfer port tunnel area.
But there have been some Extra Big BigBore cylinders done with H2 pistons and sleeves. JR
The Crankshaft
For High HP applications Shot Peening the connecting rods is recommended
2T2 rods are the best of the OEM rods
Need Hollow crank pins? I use Kawasaki 13035-1010-01
Big End Bearings
I used TZ750 big end bearings in my landspeed bike but there were less options then.
93310-422BO "They look better than stock, and even better than Wiseco silvered equivalents. They are TZ125 big end bearings" Coyote
Suzuki RM125 bearings 09263-22060 "They are silver, flat cages, good bearing life and last much longer" Lyn
Suzuki RM125 RG500 Wiseco part number is B1047 Chuck 'Supertune" Quenzler
"A common upgrade on the 73-80 TZ250/350's (and also RD350/400's) is the Suzuki RG500 big end bearing" FondsecaPiston Pin Bearings
I use OEM RG500 Big End Bearings 09263-22060 for all out racing and Wiseco RG500 part# B1047 for EVERYTHING else.
Crankshaft Main Bearings
73-80 TZ250/350/750 outer roller bearings part number 93310-00012
but these days hybrid ceramic bearings are the cats meow...
Exhaust Flange Gaskets
76-78 US spec cylinders use Suzuki 14181-01D00 They have a larger I.D.
Another (newer) option is to use Blaster exhaust flange gaskets. Supertune
Clutch Friction Plates
"1981YZ250H,1983 XS400, 1986 FZ600S, 1992 FZR1000D. XS400 plates work especially well" Dave
"FZR1000 friction plate have about 40% more surface area" M in SC Clutch
RZ350 (more surface area than the RD400 because they didn't use the large rubber "cushion rings" to reduce noise)
Steel Plates Earlier RD250/350 steel clutch plate didn't have "The balancing notches" so have more surface area or Barnett
The RD250/350 had a 6 plate clutch but that can easily be swapped out for the later 7 plate clutch
if you put an RD400 trans in an RD250/350 with the 400 clutch you will have to clearance the inside of the RD250/350 right side engine cover, or I've heard you can use a thicker side cover gasket.
There are different clutch and sprocket splines on the RD250/350 than the RD400 transmission.
RZ350/Banshee Clutch Basket and Primary Gears fit right on Rd'sStraight Cut Primary Gears
Dry clutch conversion
I've heard that HB used YZ490 parts to do this conversion
TZ250/350.(Takes a little work) Use the clutch and primary sidecover. This requires a longer mainshaft, but the stock TZ mainshaft has a higher first gear than the RD's and is part of the main shaft so you can either run the TZ transmission with higher first gear and close ratios or get a special mainshaft from this company: http://www.yamaha-tz-classicracing.de/uk/teile_getriebe.html that allows you to use an RD transmission with the TZ dry clutch parts. The TZ dryclutch cover does not come with a provision for a kickstart mechanism but I have seen several of these covers modified to use a kickstarter. I've used a billet LC cover by Metemachex to due this with a kickstarter but you have to extend the kickstart shaft 16mm. NOW Fondseca makes a dryclutch cover with the kickstart provision..
Transmission
It is highly recommended for racing that you get your transmission undercut by a company like R&D Motorsports. R&D also does transmission micro polishing and anti friction coating.
Banshee/RZ aftermarket straight cut primary gears
"According to Yamaha service bulletin 259 any spinning gear should have between .003" to .005" side play for maximum efficiency. Too little clearance and it will bind, too much and the gears can pop out of engagement causing the dogs to become rounded. Select the proper size shim and install it so the spinning gear is moved toward the sliding gear that engages it. Sizes are 20.2x33x.5,.6,.7,.8,.9, and 1.0mm (137-17427-00-05). And also 25x34x.3 and .5 (168-17428-01-03)" LynReeds
-TDR RD and RZ single petal fiber reeds, if your extensively modifying your stock reedcages ask for the Harry Barlow cut.
-1986 YZ125S reeds. "These are a 3-petal reed cut one petal off to fit your stock cages. Part number 55Y-13612-00-00" MBSteve
-Another option is the 93-2012 YZ85 reeds and trim them down just slightly at the front. These are a single petal reed but thinner than the TDR petals. Part# 4ES-13613-00-00Reedcages
Your options are:
-Modify your stock reedcages, this works great for 80% of the RD's out there, Stock cages are good for up to 70hp.
-YZ85 reedcages
-V-Force replacement cages for the RD reedcage which also fit the RZ500, and YZ85. Part number V382A (Use AG472A stuffers) Afhaldeman
-RZ350 reedcages
-RZ350/Banshee V-force replacement cages
-Or my favorite stock YZ85 reedcages with either stock reeds or TDR racing reeds part# 88-EE or V-force YZ85 for 90 percent of RD applications
Anything bigger than this and major surgery to your cylinders or replacing the whole intake reedbox is required.
Intake manifolds
RZ350 are a nice improvement and allows you to use an intake crossover tube or boost bottle. You can also get aftermarket RZ manifolds without the crossover.
Tz750 intake manifolds P/N 409-13565-00 are discontinued but TZ Mike does make very good quality reproduction manifolds.
Racing Ignitions
-Motoplat
-PVL
-HPI Racing
-HPI also makes a small external rotor ignition with lighting (M in SC)
-ProFlo (No longer available)
-TZ250/350
-MZB
-MZB also makes a CDI ignition with lighting
-If you just want to eliminate your points which is ALWAYS an improvement Vintage Smoke makes a DYNA ignition kit that bolts right on. "the problem with points is they start going bad the minute you put them on.."
RD400 Model Codes
USA Daytona Model code 2V0
Canadian Daytona model code 3J7
Oceana Daytona model code 3M4
76-78 model code 1A1 - all markets
'79 European model code 2R9
The cylinders and heads from a 1A1 will fit all years, as long as they are swapped as a complete set, along with the exhaust pipes. The cylinders, head and head gasket for the 2V0 are unique. The cylinders for the 3J7, 3M4 and 2R9 are the same. The 2R9 had separate cylinder heads and the 3J7 and 3M4 had a one piece head, they should be interchangeable. The 2R9 had separate head gaskets and the 3J7 and 3M4 had a one piece head gasket, but 2R9, 3J7 and 3M4 have the same gasket thickness, so you could use the separate gaskets on the Canadian and Oceana Daytonas.
TZR250's
1986-88 2MA - 1KT Case reed forward facing cylinders
1989-90 3MA Reverse Cylinder
Transmission Ratios
TZ250 RD400 RD250/350
.81 .888 .785
.87 .961 .888
.96 1.083 1.040
1.13 1.318 1.318
1.42 1.778 1.778
1.93 2.571 2.571
Primary Gears
RD250 68/21 3.238
RD350/400/LC/RZ 66/21 2.869
TZ250 77/23 3.35
TZ350 74/25 2.96
You are awesome Ed :nana: thank you. I really enjoy reading this stuff.
Glad to do it. I keep adding bits to it.. Just added some info 5Port from the Aircooled RD Club in the UK sent about the differences between US and UK 250,350,400's, along with some other bits. Ed
AWESOME, ED!
Great info Ed!
Great info! Thank you!
It's not just me, we're lucky, The Two-Stroke community is really like no other, Two stroke nuts I've always said are the most creative gearheads in all the world!! and most don't mind sharing with their fellow two stroke nuts, there are many other bike communities (4jokes) that never work on there own engines NOT two stroke nuts! (and especially dare I say RD/TZ/LC/RZ nuts!!)
Teazer and I put our heads together about TZ case differences so I rewrote that bit, from what we see TZ cases were different castings! yeah just a slight variation and interchangeable but a separate casting.. interesting.
-Because the R5/DS7 was the first Yamaha to have the 4 transfer port cylinder base case layout (2 on each side with a 5th boost port added in the RD series) RD, LC and early TZ cylinders will bolt directly onto the R5/DS7/RD and LC cases.
-though you do need to use the correct cylinder stud lengths (Teazer)
-BUT the R5/DS7 only had a 5 speed though it's super easy to swap out the gears, shift forks and shift drum for an RD 6 speed setup (gotta love Yamahas parts interchangeability!)
-TZ cases were a separate casting than RD cases yes a very slight variant but still a separate casting, so close though in fact when TZ racers broke early TZ cases it was super common to replace them with RD cases.
-TZ cases differ from RD cases in that:
the front engine mounts are rubber mounted,
There are grooves to locate the TZ crankshaft cut into the crankshaft inner bearing area to locate the crankshaft there instead of from the primary side bearing because the TZ's used a different crankshaft (that will interchange if you cut the grooves in RD cases) that used Roller bearing mains on the outer ends.
-There is an oil passage below the shift drum not "drilled" on TZ cases between the transmission and primary gear sections of the case and the kickstarter boss has a plug in it (Yamaha part number 90338-17016 BH) (Teazer)
The oil drain is in the middle of TZ cases but offset one the RD cases. Rd crank bearing surfaces normally have a cast in steel insert and the TZ cases normally don't. BH
so TZ cases were more than just RD cases machined for front engine mounts.
- Early TZ's had a different transmission, though it would drop right in RD cases it has a VERY tall first gear and much closer gear ratio with a longer mainshaft to allow for the TZ dry clutch.
-The TZ dry clutch if combined with the TZ transmission or an RD transmission with a special mainshaft will bolt directly into an RD
-A TZ dry clutch with a special mainshaft will bolt directly on to an LC
A TZ dry clutch (with a special mainshaft) and slight modification for gasket sealing to the cases will bolt onto an RZ.
Quote from: Jspooner on July 11, 2019, 04:50:08 PM
Quote from: motodreams on July 11, 2019, 04:22:01 PM
Are there any side covers that are interchangeable with the RD350LC? Maybe a RD400? I am still looking for a solution for the hard to find clutch actuator mechanism missing on my LC...
Yes, RD400 fits perfectly, you just have to make some room for the electronic ignition trigger for the LC. Ill take a pic of mine and post it in a bit.
Was that an RD cover with TZ (replica?) rear cover and ignition cover? Nice way to get a TZ side cover. And for anyone that prefers the vertical mid-mounted RD type clutch cable, they can cut a slot in the crankcases.
Nice research Ed. I'll send you some pictures of different crankcases as soon as I get them into some sort of shape.
If anyone has pictures of Euro RD250 c-f cases (bare) that would be great to see them.
Quote from: teazer on July 23, 2019, 08:09:00 PM
Quote from: Jspooner on July 11, 2019, 04:50:08 PM
Quote from: motodreams on July 11, 2019, 04:22:01 PM
Are there any side covers that are interchangeable with the RD350LC? Maybe a RD400? I am still looking for a solution for the hard to find clutch actuator mechanism missing on my LC...
Yes, RD400 fits perfectly, you just have to make some room for the electronic ignition trigger for the LC. Ill take a pic of mine and post it in a bit.
Was that an RD cover with TZ (replica?) rear cover and ignition cover? Nice way to get a TZ side cover. And for anyone that prefers the vertical mid-mounted RD type clutch cable, they can cut a slot in the crankcases.
That's exactly what it is.
Alright so I was going to add Cylinder stud lengths and just got the "you cannot exceed 20000 characters!!!!" messaged so I cleaned things up a bit and i'll try to post the new compilation in the next post..
History and differences between RD250,350,400, 73-80 TZ, LC, and RZ engines
(from the 1970 DS7/R5 to the 1990 reverse cylinder TZ250)
(Note: for ease of reference I refer to 73-80 TZ's as "early TZ's" because the cases interchange)
-1962 The RD56 Yamahas first World Grand Prix Champion winner (56x50 rotary valve 250)
-1967 The YR1 Yamahas first horizontally split parallel twin (61x61 350 / 2 tranfer piston port cylinders)
-1970-1972 DS7/R5 start of the 4 transfer port cyl base/cases layout that form the basis for the RD and early TZ series
-DS7 / TD3 250
-R5 / TR3 350
-TA250 early 1973 aircooled TD3/TZ hybrid
-An interesting point: The some of the "works" TR3 engines from 1972 sported 6 transfer ports, like an F/G model 350.
-1973-1980 TZ's used a variant of the "RD" cases but used Piston ported monoblock watercooled cylinders
-The TZ250 G in a last ditch effort to get ever last hp out of the "RD" based case engines ran an intake so big it became know as the piston eater..
-In 1981Yamaha totally redesigned the TZ250 engine. Having reached the limit of intake port size in the G, the H models crankshaft rotation was run backwards to put piston thrust on the cylinder wall opposite the intake allowing further increases in intake port size. The cylinders were now individual but still piston port. Also new was Yamaha's exhaust power valve system which in it's infancy was having teething problems.
-In 1985 Yamaha again Redesigned the TZ250 engine. 1985-1987. Switching for the first time to case reed induction allowing for much needed transfer area (2 new boost ports were the intake once was) creating needed bottom end & thereby also a wider powerband. BUT 1985's reedcages were to small and were quickly enlarged.
-In 1988 through 90 in a last ditch effort to get every last hp out of the parallel twin design Yamaha reversed the cylinders & tilted them forward to 60deg putting the carbs in front & the pipes coming straight out the back under the seat.
-Because the R5/DS7 was the first Yamaha to have the 4 transfer port cylinder base case layout (2 on each side with a 5th boost port added in the RD series) RD, LC and early TZ cylinders will bolt directly onto the R5/DS7/RD and LC cases.
-though you do need to use the correct cylinder stud lengths (Teazer)
-BUT the R5/DS7 only had a 5 speed though it's super easy to swap out the gears, shift forks and shift drum for an RD 6 speed setup (gotta love Yamahas parts interchangeability!)
-TZ cases were a separate casting than RD cases yes a very slight variant but still a separate casting, so close though in fact when TZ racers broke early TZ cases it was super common to replace them with RD cases.
-TZ cases differ from RD cases in that:
the front engine mounts are rubber mounted,
There are grooves to locate the TZ crankshaft cut into the crankshaft inner bearing area to locate the crankshaft there instead of from the primary side bearing because the TZ's used a different crankshaft (that will interchange if you cut the grooves in RD cases) that used Roller bearing mains on the outer ends.
-There is an oil passage below the shift drum not "drilled" on TZ cases between the transmission and primary gear sections of the case and the kickstarter boss has a plug in it (Yamaha part number 90338-17016 BH) (Teazer)
The oil drain is in the middle of TZ cases but offset one the RD cases. The center RD crank bearing surfaces normally have a cast in steel insert and the TZ cases normally don't. BH
so TZ cases were more than just RD cases machined for front engine mounts.
- Early TZ's had a different transmission, though it would drop right in RD cases it has a VERY tall first gear and much closer gear ratios with a longer mainshaft to allow for the TZ dry clutch.
-The TZ dry clutch if combined with the TZ transmission or an RD transmission with a special mainshaft will bolt directly into an RD
-A TZ dry clutch with a special mainshaft will bolt directly on to an LC
A TZ dry clutch (with a special mainshaft) and slight modification for gasket sealing to the cases will bolt onto an RZ.
-DS7/R5 cases had no grooves in the crankshaft seal area to secure the seal as everything RD and later does. And they did not have the mainshaft clutch side bearing retainer behind the clutch.
-According to the aircooled RD club early RD400 Prototypes had solid mounted engine mounts!
-RD400 cases have slight differences in the castings, the earliest had a little less material around the cylinder base gasket area at the rear and more ribbing around the right main bearing for sure (and right transmission mainshaft bearing if memory serves me correctly) in later cases.
-Starting with Daytona in the US and later UK cases used a different kickstarter mechanism. Daytona could use either kickstart mechanism, I "was told' back in the day that the gear on the "Daytona style" kickstart mechanism which on this new design was not constantly engaged with the idler gear like the earlier mechanism is in racing had slid over and engaged on some racers so common practice was to retrofit the old system when using "Daytona' cases. I did have one customer that would not take no for an answer so I used a throttle slide return spring to keep the kickstart gear positively disengaged when not in use. One drawback with the "Daytona" style kickstart mechanism was that it kicked over more slowly as well. This style also used a "single" offset idler/tach drive gear instead of the 2 gears pressed together of the earlier style since it drove the tach.
-EarlyTZ's used this gear also but ran it with a neeedle bearing. Later RZ's used the "single" gear but added a bushing to it.
-Since Daytona and later RD's used the single gear kickstart idler gear they used a longer tach drive shaft and internal gear ratio in the case right before the cable, also a smaller tach drive nylon gear
-TZ250 and 350 had different primary gear ratios than the RD's so they used 2 different nylon tach drive gears (and 2 different water pump drive gears)
-While the rest of the world got electronic ignition in 79/80 we didn't here in the states..
-The Daytona, got a new crankshaft without the dreaded lead weights but improper heat treating it's believe causes them to snap the center section under racing conditions..
-Later UK RD400 and RD250 did get this style of crankshaft though with the larger LC/RZ style ignition taper for the electronic ignition they got but I'm told those did not have the racing center crankshaft snapping problem.
-LC's went a step further and went to the now well know RZ/Banshee style crankshaft but the LC's still had a 16mm wide big end bearing (RZ widened to 17) with large big end and wrist pin bearing outer diameters.
-An LC crankshaft will fit in Aircooled RD cases, but you need to mod the end of the crank, OR 'doghouse' the RH cover to take the longer crank. (no oil pump can be used after this mod) the LC crank also allows for a large taper cdi to be used, and yes, an rz or lc cdi will then bolt right on to aircooled cases. you will need to clearance the LH cover to accommodate the cdi pickup though.
-An RZ crankshaft is a mm too wide to drop right into RD/LC cases but have been made to fit.
-The keyway on a Daytona crank is 90 degrees off the LC and RZ cranks
-RZ cylinders while they would work on RD case have a much different cylinder base stud pattern, but the cylinder center to center spacing and heights are the same as a RD and LC 350 they will "slip in" they just won't bolt up
-The RZ right side cover/water pump will not work on an RD set of cases because they are missing the rear water pipe passage and the boss to support the pump shaft.
- RZ and LC have a longer right crank snout than an RD to take the water pump drive gear.
-Some have used the wider RZ rods in RD's on RD cranks by machining .5mm off the inside of each crankweb.
-An RZ clutch cover will almost fit onto an RD set of cases but the RZ have a little more metal in two places. Teazer
-An RD clutch cover can be made to run a TZ water pump, the TZ waterpump will be driven through the original oil pump drive shaft hole, but it does require an adapter to fit under the pump.
-LC and RZ use the same kickstarter arrangement/mechanism. Similar to the Daytona and later UK RD's On the RZ/LC the inner end of the short kickstarter shaft is a smaller diameter than RD's, so either the cases needs to be bushed or a sleeve pressed onto the shaft. The shaft is longer than an Air cooled motor which is fine if you use an RZ clutch cover. This can only directly be done on Daytona and later UK cases as there is a different style locator spring boss in those cases (unless of course I suppose you weld and machine one..)
-The RZ/LC kickstart shaft is considerably longer than RD's, twice to use an LC side cover I grafted two early style RD kickstart shafts together to extend them 17mm.
-LC and RZ transmissions use three shift forks and not 4 as in the RD's
-Unlike the RZ, LC's still had the clutch pushrod that went all the way through and out the left side of the cases to a clutch actuator in the left side cover.
-You can run RZ/Banshee primaries on an RD I've done it a number of times
-The Daytona and later left side covers had a provision for the electronic ignition pickup
-The Daytona had thinner primary gears
-The Daytona 5th and 6th gears had thinner engagement dogs which made them easier to shift into these gears but not good for racing..
-The Daytona and later used a different shift mechanism ratio
-76-78 US RD400's had a small cutout at the bottom of the skirt on the exhaust side for emissions reasons that actually let ex gasses into the crankcase at TDC! the Daytona did not have this cutout because it used external exhaust butterfly valves between the cylinders and exhaust pipes for emissions reasons so the trick was to use Daytona pistons in all the 64mm bore RD's at least until RZ (and LC) pistons came out.
-76-78 US Rd400's also came with an small exhaust bleed port from the roof of the exhaust port tunnel to approximately 10mm above the exhaust port, in performance applications it's standard practice to plug and weld these closed.
-All year RD350's in the US had Dykes ring pistons (not good for racing...)
- An RD400 left side cover will fit an LC perfectly, you just have to make some room for the electronic ignition trigger for the LC. JSpooner
Here are some engine model differences between US and UK 250/350/400's from a European viewpoint. 5Port
R5/DS7 Cases sometimes do have the shallow recess for the early RD type crankseals. No idea when that changed, just can be seen on some cases.
RD250/350. Euro 351/352 models have a blocked 6th gear (different pawl plate in selector segment pins). Different sprockets to raise final drive ratio.
RD250/350B. Euro 521/522 models have 521 Model carbs, cylinderheads, gearbox and exhausts. The gearbox has all 6 speeds available and has the same ratio's of the later 250/400 with overall closer ratio's and revised final drive ratio.
RD250/400C/D. Euro 1A2 (250) and 1A3 (400). Similar to 1A1. Gearbox shafts have later type splines. Cylinderheads are marked 1A0 (250) and 1A3 (400), different casting to 1A1.
RD250/400E. 2R8/2R9. "TZ" style crank with no lead weights and slotted rods. Revised cylinders, porting and CR. Revised 400 pistons without front cut-out in skirt. CDI ignition. Revised LHS case cover with bulge over CDI pick-up coil. Gearbox and shifter changes. Narrow primary gears. Revised carbs and small X-over tube on 400. Revised 2R8/2R9 big-bore downpipes and silencers. 5Port
-Banshees had different transmission gear ratios than the RZ most everything else interchanges
RD250/350/400 Performance Parts Upgrades
RZ350 or Banshee pistons are a far superior piston than the stock pistons.
Of the cast pistons OEM are arguably the best, then Vertex, then Pro-X
Of the forged pistons Wossner, then Wiseco
The center tab at the bottom of these pistons must be removed thought (very easy),
And Vertex must be trimmed a bit if used in an RD400.
For Racing Bigbore Topends (66mm and up)
1980 IT/DT 175 pistons or Yamaha Blaster Pistons. Either piston is 5-6mm shorter than stock and requires machining the top & bottom of the cylinder to compensate for the height. The blaster pistons also have a 10deg piston dome instead of the RD/RZ/IT/DT 15deg so it does require reccutting the cylinder heads (but if your doing a bigbore you need to recutt the cylinder heads anyway)
Sleeving these cylinders is not ideal because of the decreased heat dissipation from the pressed in replacement sleeve and the fact that the thickness of a replacement sleeve cuts into the already limited transfer port tunnel area.
But there have been some Extra Big Big Bore cylinders done with H2 pistons and sleeves. JR
The Crankshaft
For High HP applications Shot Peening the connecting rods is recommended
2T2 rods are the best of the OEM rods
Need Hollow crank pins? I use Kawasaki 13035-1010-01
Big End Bearings
I used TZ750 big end bearings in my landspeed bike but there were less options then.
93310-422BO "TZ125 big end bearings" Coyote
Suzuki RG500/RM125 bearings 09263-22060 Lyn
Suzuki RM125 RG500 Wiseco part number is B1047 Supertune
I use OEM RG500 Big End Bearings 09263-22060 for all out racing and Wiseco RG500 part# B1047 for EVERYTHING else. EE
Crankshaft Main Bearings
73-80 TZ250/350/750 outer roller bearings part number 93310-00012
but these days hybrid ceramic bearings are the way to go.
Exhaust Flange Gaskets
76-78 US spec cylinders use Suzuki 14181-01D00 They have a larger I.D.
A newer option though is to use Blaster exhaust flange gaskets. Supertune
Clutch Friction Plates
"1981YZ250H,1983 XS400, 1986 FZ600S, 1992 FZR1000D. XS400 plates work especially well" Dave
"FZR1000 friction plate have about 40% more surface area" M in SC Clutch
RZ350 (more surface area than the RD400 because they didn't use the large rubber "cushion rings" to reduce noise)
Steel Plates Earlier RD250/350 steel clutch plate didn't have "The balancing notches" so have more surface area or Barnett
The RD250/350 had a 6 plate clutch but that can easily be swapped out for the later 7 plate clutch
if you put an RD400 trans in an RD250/350 with the 400 clutch you will have to clearance the inside of the RD250/350 right side engine cover, or I've heard you can use a thicker side cover gasket.
There are different clutch and sprocket splines on the RD250/350 than the RD400 transmission.
RZ350/Banshee Clutch Basket and Primary Gears fit right on Rd's
Dry clutch conversion
I've heard that HB used YZ490 parts to do this conversion
TZ250/350.(Takes a little work) Use the clutch and primary sidecover. This requires a longer mainshaft, but the stock TZ mainshaft has a higher first gear than the RD's and is part of the main shaft so you can either run the TZ transmission with higher first gear and close ratios or get a special mainshaft from this company: http://www.yamaha-tz-classicracing.de/uk/teile_getriebe.html that allows you to use an RD transmission with the TZ dry clutch parts. The TZ dryclutch cover does not come with a provision for a kickstart mechanism but I have seen several of these covers modified to use a kickstarter. I've used a billet LC cover by Metemachex to due this with a kickstarter but you have to extend the kickstart shaft 17mm. NOW Fondseca makes a dryclutch cover with the kickstart provision..
Transmission
It is highly recommended for racing that you get your transmission undercut by a company like R&D Motorsports. R&D also does transmission micro polishing and anti friction coating.
Banshee/RZ aftermarket straight cut primary gears
"According to Yamaha service bulletin 259 any spinning gear should have between .003" to .005" side play for maximum efficiency. Too little clearance and it will bind, too much and the gears can pop out of engagement causing the dogs to become rounded. Select the proper size shim and install it so the spinning gear is moved toward the sliding gear that engages it. Sizes are 20.2x33x.5,.6,.7,.8,.9, and 1.0mm (137-17427-00-05). And also 25x34x.3 and .5 (168-17428-01-03)" LynReeds
-TDR RD and RZ single petal fiber reeds, if your extensively modifying your stock reedcages ask for the Harry Barlow cut it's a tapered reed that completely covers the reedcage surface area.
-1986 YZ125S reeds. "These are a 3-petal reed cut one petal off to fit your stock cages. Part number 55Y-13612-00-00" MBSteve
-Another option is the 93-2012 YZ85 reeds and trim them down just slightly at the front. These are a single petal reed but thinner than the TDR petals. Part# 4ES-13613-00-00Reedcages
Your options are:
-Modify your stock reedcages, this works great for 80% of the RD's out there, Stock cages are good for up to 70hp.
-YZ85 reedcages
-V-Force replacement cages for the RD reedcage which also fit the RZ500, and YZ85. Part number V382A (Use AG472A stuffers) Afhaldeman
-RZ350 reedcages
-RZ350/Banshee V-force replacement cages
-Or my favorite stock YZ85 reedcages with either stock reeds or TDR racing reeds part# 88-EE or V-force YZ85 for 90 percent of RD applications
Anything bigger than this and major surgery to your cylinders or replacing the whole intake reedbox is required.
Intake manifolds
RZ350 are a nice improvement and allows you to use an intake crossover tube or boost bottle. You can also get aftermarket RZ manifolds without the crossover.
Tz750 intake manifolds P/N 409-13565-00 are discontinued but TZ Mike does make very good quality reproduction manifolds.
Racing Ignitions
-Motoplat
-PVL
-HPI Racing
-HPI also makes a small external rotor ignition with lighting (M in SC)
-ProFlo (No longer available)
-TZ250/350
-MZB
-MZB also makes a CDI ignition with lighting
-If you just want to eliminate your points which is ALWAYS an improvement Vintage Smoke makes a DYNA ignition kit that bolts right on. Like I always say "the problem with points is they start going bad the minute you put them on.."
RD400 Model Codes
USA Daytona Model code 2V0
Canadian Daytona model code 3J7
Oceana Daytona model code 3M4
76-78 model code 1A1 - all markets
'79 European model code 2R9
The cylinders and heads from a 1A1 will fit all years, as long as they are swapped as a complete set, along with the exhaust pipes. The cylinders, head and head gasket for the 2V0 are unique. The cylinders for the 3J7, 3M4 and 2R9 are the same. The 2R9 had separate cylinder heads and the 3J7 and 3M4 had a one piece head, they should be interchangeable. The 2R9 had separate head gaskets and the 3J7 and 3M4 had a one piece head gasket, but 2R9, 3J7 and 3M4 have the same gasket thickness, so you could use the separate gaskets on the Canadian and Oceana Daytonas.
TZR250's
1986-88 2MA - 1KT Case reed forward facing cylinders
1989-90 3MA Reverse Cylinder
Transmission Ratios
TZ250 RD400 RD250/350
.81 .888 .785
.87 .961 .888
.96 1.083 1.040
1.13 1.318 1.318
1.42 1.778 1.778
1.93 2.571 2.571
Primary Gears
RD250 68/21 3.238
RD350/400/LC/RZ 66/21 2.869
TZ250 77/23 3.35
TZ350 74/25 2.96
Cylinder Studs
RD 250 90116-08065-00 90mm(72-73mm sticks out of casing)
RD350 90116-08064-00 97mm (80-81mm sticks out of casing)
RD 400 90116-08232-00 117mm (98mm sticks out of casing)
TZ250 90116-08213-00 94mm
TZ350 90116-08212-00 101mm
TZ750 90116-08212-00 101mm
RD250LC/RD350LC 90116-08219-00 106mm
So I asked the guys on the RD LC crazy and RZ forums for a bit of input on LC to RZ differences and got a bit more input. This should be about it. Ed
Bear with me I went over the 20,000 character limit again!!!
Quote from: EE on July 09, 2019, 05:22:35 PM
Probably the thing that has given me the most enjoyment over the years working on RD's is that on an average guys budget with hard work (lots of time, lots of thought, lots of more thought and lots of more hard work yes..) and the patient and persistent application of good science (and yes more hard work..) these bikes can very often just honestly do "more than their supposed to be able to do".... You gotta love em, don't let anybody tell you their not the race bred descendents of the RD56 like their racing cousins like I tell guys when their on the pipe they don't know their not TZ's!!! Gotta love em, all that rolled up in aircoooled simplicity.. No RD's are not CPI cylindered RZ/Banshee megabuck motors but dam can they perform with a lot of hard work and good science.. Ed
:good: YES!!!
History and differences between RD250,350,400, 73-80 TZ, LC, and RZ engines
(From the 1970 DS7/R5 to the 1990 reverse cylinder TZ250)
(Note: for ease of reference I refer to 73-80 TZ's as "early TZ's")
1962 The RD56 Yamahas first World Grand Prix Champion winner (56x50 rotary valve 250)
1967 The YR1 Yamahas first horizontally split parallel twin (61x61 350 2 transfer piston port)
1970-1972 DS7/R5 start of the 4 transfer port cyl base/case layout that form the basis for the RD and early TZ series
DS7 / TD3 250
R5 / TR3 350
TA250 early 1973 aircooled TD3/TZ hybrid
An interesting point: The some of the "works" TR3 engines from 1972 sported 6 transfer ports, like the 79/80 TZ350
1973-1980 TZ's used a variant of the "RD" cases but used Piston port monoblock watercooled cylinders
1980 the TZ250 G in a last ditch effort to get ever last hp out of the "RD" based case engines ran an intake so big it became know as the piston eater
1981Yamaha totally redesigned the TZ250 engine. Having reached the limit of intake port size in the G, the H models crankshaft rotation was run backwards to put piston thrust on the cylinder wall opposite the intake allowing further increases in intake port size. The cylinders were now individual but still piston port. Also new was Yamaha's exhaust power valve system
1985 Yamaha again Redesigned the TZ250 engine. 1985-1987. Switching for the first time to case reed induction to create much needed bottom end and widen the powerband. BUT 1985's reedcages were to small and were quickly enlarged
1988-90 in a last ditch effort to get every last hp out of the parallel twin design Yamaha reversed the cylinders & tilted them forward to 60deg putting the carbs in front & the pipes coming straight out the back under the seat
Because the R5/DS7 was the first Yamaha to use the 4 transfer port cylinder base case layout (2 on each side with a 5th boost port added in the RD series) RD, LC and early TZ cylinders will bolt directly onto the R5/DS7/RD and LC cases.
though you do need to use the correct cylinder stud lengths (Teazer)
BUT the R5/DS7 only had a 5 speed but it is super easy to swap out the gears, shift forks and shift drum for an RD 6 speed setup
TZ cases were a separate casting than RD cases, a very slight variant but still a separate casting, so close though in fact that when TZ racers broke early TZ cases it was super common to replace them with RD cases
TZ cases differ from RD cases in that
the front engine mounts are rubber mounted,
The grooves to locate the TZ crankshaft are cut into the crankshaft inner bearing area instead of the primary side bearing area because the TZ's used a different crankshaft (that will interchange if you cut the grooves in RD cases) that used Roller bearing outer main bearings
There is an oil passage below the shift drum not "drilled" on TZ cases between the transmission and primary gear sections of the case and the kickstarter boss has a plug in it (Yamaha part number 90338-17016 BH) (Teazer)
The oil drain is in the middle of TZ cases but offset one the RD cases. The center RD crank bearing surfaces normally have a cast in steel insert buy the TZ cases normally don't BH
so TZ cases were more than just RD cases machined for front engine mounts
Early TZ's had a different transmission, though it can drop right in RD cases it has a VERY tall first gear and much closer gear ratios with a longer mainshaft to allow for the TZ dry clutch
The TZ dry clutch if combined with the TZ transmission or an RD transmission with a special mainshaft will bolt directly into an RD
A TZ dry clutch with a special mainshaft will bolt directly on to an LC
A TZ dry clutch with a special mainshaft and slight modification for gasket sealing to the cases will bolt onto an RZ
Almost all DS7/R5 cases had no grooves in the crankshaft seal area to secure the seal as everything RD and later does but I'm told some did. And they did not have the mainshaft clutch side bearing retainer behind the clutch
According to the aircooled RD club early RD400 Prototypes had solid mounted engine mounts!
RD400 cases have slight differences in the castings, the earliest had a little less material around the cylinder base gasket area at the rear and more ribbing around the right main bearing and right transmission mainshaft bearing in later cases.
Starting with Daytona in the US and later UK cases used a different kickstarter mechanism. Daytona could use either kickstart mechanism, I was told back in the day that the gear on the "Daytona style" kickstart mechanism which on this new design was not constantly engaged with the idler gear like the earlier mechanism, in racing had slid over and engaged on some racers so common practice was to retrofit the old system when using "Daytona' cases. I did have one customer that would not take no for an answer so I used a cut down throttle slide return spring to keep the kickstart gear positively disengaged when not in use. One drawback with the "Daytona" style kickstart mechanism is that it does kick over more slowly . This style also used a "single" offset idler/tach drive gear instead of the 2 gears pressed together of the earlier style.
EarlyTZ's used this "double gear" also but ran it with a needle bearing. Later RZ's used the "single" gear but added a bushing to it
Since Daytona and later RD's used the single gear kickstart idler gear they used a longer tach drive shaft, a smaller nylon tach drive gear and a different tach drive ratio
TZ250 and 350 had different primary gear ratios than the RD's so they used 2 different nylon tach drive gears (and 2 different water pump drive gears)
While the rest of the world got electronic ignition in 79/80 the US didn't
The Daytona, got a new crankshaft without the dreaded lead weights but improper heat treating it's believed caused them to snap the center section under racing conditions
Later UK RD400 and RD250 did get this style of crankshaft though with the larger LC/RZ style ignition taper for the electronic ignition they got but I'm told those did not have the racing center crankshaft snapping problem.
LC's went a step further and went to the now well know RZ/Banshee style crankshaft but the LC's still had a 16mm wide big end bearing (RZ widened to 17) with larger big end and wrist pin bearing outer diameters
An LC crankshaft will fit in Aircooled RD cases, but you need to mod the end of the crank, OR 'doghouse' the RH cover to take the longer crank. (no oil pump can be used after this mod) the LC crank also allows for a large taper cdi to be used, and yes, an RZ or LC cdi will then bolt right on to aircooled cases. you will need to clearance the LH cover to accommodate the cdi pickup though
An RZ crankshaft is aprox 2 mm too wide to drop right into RD/LC cases but have been made to fit.
The keyway on a Daytona crank is 90 degrees off the LC and RZ cranks
RZ cylinders while will "slip in" to RD cases but have a much different cylinder base stud pattern, the cylinder center to center spacing and heights are the same as a RD and LC 350 they just won't bolt up
The RZ right side cover/water pump will not work on an RD set of cases because they are missing the rear water pipe passage and the boss to support the pump shaft
RZ and LC have a longer right crank snout than an RD to take the water pump drive gear
Some have used the wider RZ rods on RD cranks by machining .5mm off the inside of each crankweb
An RZ clutch cover will almost fit onto an RD set of cases but the RZ have a little more metal in two places Teazer
An RD clutch cover can be made to run a TZ water pump, the TZ waterpump will be driven through the original oil pump drive shaft hole, but it does require an adapter to fit under the pump
LC and RZ use the same kickstarter arrangement/mechanism. Similar to the Daytona and later UK RD's On the RZ/LC the inner end of the kickstarter shaft is a smaller diameter than RD's, so either the cases needs to be bushed or a sleeve pressed onto the shaft. The outer portion of the shaft is longer than an Air cooled motor which is fine if you use an LC or RZ clutch cover. This can only directly be done on Daytona and later UK cases as there is a different style locator spring boss in those cases (unless of course you weld and machine the cases)
Twice to use an LC side cover I grafted two early style RD kickstart shafts together to extend the kickstart mechanism the needed 17mm.
You can run RZ/Banshee primaries on an RD I've done it many times
The Daytona and later left side covers had a provision for the electronic ignition pickup
The Daytona had thinner primary gears
The Daytona 5th and 6th gears had thinner engagement dogs which made them easier to shift into these gears but not good for racing
The Daytona and later used a different shift mechanism ratio
76-78 US RD400's had a small cutout at the bottom of the skirt on the exhaust side for emissions reasons that actually let ex gasses into the crankcase at TDC The Daytona did not have this cutout because it used vacuum controlled external exhaust butterfly valves to accomplish the same result so the trick was to use Daytona pistons in all the 64-65mm bore RD's at least until RZ (and LC) pistons came out.
76-78 US Rd400's also came with an small exhaust bleed port in the roof of the exhaust port approximately 10mm above the port, in performance applications it's standard practice to plug and weld these closed
All year RD350's in the US had Dykes ring pistons (not good for racing)
An RD400 left side cover will fit an LC perfectly, you just have to make some room for the electronic ignition trigger for the LC Jspooner
The LC and RZ bottom ends are very similar
The crank width was the same from RD to LC but they did widen the trans gearset making the gears wider
The RZ crank width increased slightly (approx 2mm) and with it another increase in gearset width and shift drum. Gears differ but the RZ uses a few of the LC's gears I counted 3 with the LC 4L0 prefix, both changed to the "shiftstar" type gear change mechanism. LC and RZ crankcase mount dimensions are the same, but differ largely than the aircooled RDs. LC/RZ engines have 2 mounting points, aircooleds have 4. Aircooled RD's had a first gear needle roller bearing were the LC went to a bushing there Tacky/Dusty
LC and RZ transmissions use three shift forks and not 4 as in the RD's
Unlike the RZ, LC's still had the clutch pushrod that went all the way through and out the left side of the cases to a clutch actuator in the left side cover
LC/RZ use the same shift forks . Tach gear assemblies are the same LC and 83-84 and US 85 RZ . Clutch basket/ primary gears are interchangeable. Clutch hub , LC clutch cover will fit the RZ , same gasket for both . Oil pump are interchangeable , 1979-80 RD400 2R9 , LC and RZ . Coolant pump , LC and RZ . Reed valves , RD350 , RD400 and LC plus RZ500 . Carburetor manifold and balance tube ,1979-80 RD400 2R9 and LC . Motor mounts with spacers , LC and RZ and stays under the motor to the frame Zedixie13
Here are some engine model differences between US and UK 250/350/400's from a European viewpoint
RD250/350. Euro 351/352 models have a blocked 6th gear (different pawl plate in selector segment pins)
RD250/350B. Euro 521/522 models have 521 cylinder heads and gearbox. The gearbox has all 6 speeds available and has the same ratio's of the later 250/400 with overall closer ratio's
RD250/400C/D. Euro 1A2 (250) and 1A3 (400). Similar to 1A1. Gearbox shafts have later type splines. Cylinder heads are marked 1A0 (250) and 1A3 (400), different casting to 1A1
RD250/400E. 2R8/2R9. "TZ" style crank with no lead weights and slotted rods. Revised cylinders, porting and CR. Revised 400 pistons without front cut-out in skirt. CDI ignition. Revised LHS case cover with bulge over CDI pick-up coil. Gearbox and shifter changes. Narrow primary gears. Small "LC" X-over tube on 400. 5Port
Banshees had different transmission gear ratios than the RZ most everything else interchanges between the two
RD250/350/400 Performance Parts Upgrades
RZ350 or Banshee pistons are a far superior piston than the stock RD pistons.
Of the cast pistons OEM are arguably the best, then Vertex, then Pro-X
Of the forged pistons Wossner, then Wiseco
The center tab at the bottom of these pistons must be removed thought (very easy),
And Vertex must be trimmed a bit if used in an RD400.
For Racing Bigbore Topends (66mm and up)
1980 IT/DT 175 pistons or Yamaha Blaster Pistons. Either piston is 5-6mm shorter than stock and requires machining the top & bottom of the cylinder to compensate for the height. The blaster pistons also have a 10deg piston dome instead of the RD/RZ/IT/DT 15deg so it does require reccutting the cylinder heads (but if your doing a bigbore you need to recut the cylinder heads anyway)
Sleeving these cylinders is not ideal because of the decreased heat dissipation from the pressed in replacement sleeve and the fact that the thickness of a replacement sleeve cuts into the already limited transfer port tunnel area.
There have been some Extra Big Big Bore cylinders done with H2 pistons and sleeves. JR
The Crankshaft
For High HP applications Shot Peening the connecting rods is recommended
2T2 rods are the best of the OEM rods
Need Hollow crank pins? I use Kawasaki 13035-1010-01
Big End Bearings
I used TZ750 big end bearings in my landspeed bike but there were less options then
93310-422BO "TZ125 big end bearings" Coyote
Suzuki RG500/RM125 bearings 09263-22060 Lyn
Suzuki RM125 RG500 Wiseco part number is B1047 Supertune
I use OEM RG500 Big End Bearings 09263-22060 for all out racing and Wiseco RG500 part# B1047 for EVERYTHING else
Crankshaft Main Bearings
73-80 TZ250/350/750 outer roller bearings part number 93310-00012
but these days hybrid ceramic bearings are the way to go
Exhaust Flange Gaskets
76-78 US spec cylinders use Suzuki 14181-01D00 They have a larger I.D.
A newer option though is to use Blaster exhaust flange gaskets Supertune
Clutch Friction Plates
"1981YZ250H,1983 XS400, 1986 FZ600S, 1992 FZR1000D. XS400 plates work especially well" Dave
"FZR1000 friction plate have about 40% more surface area" M in SC Clutch
RZ350 (more surface area than the RD400 because they didn't use the large rubber "cushion rings" to reduce noise)
Steel Plates Earlier RD250/350 steel clutch plate didn't have "The balancing notches" so have more surface area or Barnett
The RD250/350 had a 6 plate clutch but that can easily be swapped out for the later 7 plate clutch
if you put an RD400 trans in an RD250/350 with the 400 clutch you will have to clearance the inside of the RD250/350 right side engine cover, or I've heard you can use a thicker side cover gasket.
There are different clutch and sprocket splines on the RD250/350 than the RD400 transmission
RZ350/Banshee Clutch Basket and Primary Gears fit right on to Rd's
Dry clutch conversion
I've heard that HB used YZ490 parts to do this conversion
TZ250/350.(Takes a little work) Use the clutch and primary sidecover. This requires a longer mainshaft, but the stock TZ mainshaft has a higher first gear than the RD's and is part of the main shaft so you can either run the TZ transmission with higher first gear and close ratios or get a special mainshaft from this company: http://www.yamaha-tz-classicracing.de/uk/teile_getriebe.html that allows you to use an RD transmission with the TZ dry clutch parts. The TZ dryclutch cover didn't come with a provision for a kickstart mechanism but I have seen several of these covers modified to use a kickstarter. I've used a billet LC cover by Metemachex to do this with a kickstarter but you have to extend the kickstart shaft 17mm. NOW Fondseca makes a dryclutch cover with the kickstart provision
Transmission
It is highly recommended for racing that you get your transmission undercut by a company like R&D Motorsports. R&D also does transmission micro polishing and anti friction coating
"According to Yamaha service bulletin 259 any spinning gear should have between .003" to .005" side play for maximum efficiency. Too little clearance and it will bind, too much and the gears can pop out of engagement causing the dogs to become rounded. Select the proper size shim and install it so the spinning gear is moved toward the sliding gear that engages it. Sizes are 20.2x33x.5,.6,.7,.8,.9, and 1.0mm (137-17427-00-05). And also 25x34x.3 and .5 (168-17428-01-03)" LynReeds
Reeds and Reed Cages our options are:
Use the stock reedcage with a single petal reed from TDR or 93-2012 YZ85 reeds trimmed down just slightly at the front. These are a single petal reed but thinner than the TDR petals Or
1986 YZ125S reeds. "These are a 3-petal reed cut one petal off to fit your stock cages. Part number 55Y-13612-00-00" MBSteve
Stock cages are good for up to 70hp.
Modify your stock reedcages by removing the center divider and using single petal reeds, this works great for 80% of the RD's out there,
If your extensively modifying your stock reedcages ask for the Harry Barlow cut it's a tapered reed that completely covers the reedcage surface area
Stock YZ85 reedcages
V-Force YZ85 reedcages. Part number V382A (Use AG472A stuffers) Afhaldeman
RZ350 reedcages
RZ350/Banshee V-force reed cages
My favorite for 90 percent of RD applications is stock YZ85 reedcages with either stock reeds or TDR racing reeds part# 88-EE or V-force YZ85 reedcages.
Anything bigger than this and major surgery to your cylinders or replacing the whole intake reedbox is required
Intake manifolds
RZ350 are a nice improvement and allows you to use an intake crossover tube or boost bottle. You can also get aftermarket RZ manifolds without the crossover
Tz750 intake manifolds P/N 409-13565-00 are discontinued but TZ Mike does make very good quality reproduction manifolds.
Racing Ignitions
Motoplat
PVL
HPI Racing
HPI also makes a small external rotor ignition with lighting (M in SC)
ProFlo (No longer available)
TZ250/350
MZB
MZB also makes a CDI ignition with lighting
If you just want to eliminate your points which is ALWAYS an improvement Vintage Smoke makes a DYNA ignition kit that bolts right on.
RD400 Model Codes
USA Daytona Model code 2V0
Canadian Daytona model code 3J7
Oceana Daytona model code 3M4
76-78 model code 1A1 - all markets
'79 European model code 2R9
The cylinders and heads from a 1A1 will fit all years, as long as they are swapped as a complete set, along with the exhaust pipes. The cylinders, head and head gasket for the 2V0 are unique. The cylinders for the 3J7, 3M4 and 2R9 are the same. The 2R9 had separate cylinder heads and the 3J7 and 3M4 had a one piece head, they should be interchangeable. The 2R9 had separate head gaskets and the 3J7 and 3M4 had a one piece head gasket, but 2R9, 3J7 and 3M4 have the same gasket thickness, so you could use the separate gaskets on the Canadian and Oceana Daytonas
TZR250's
1986-88 2MA - 1KT Case reed forward facing cylinders
1989-90 3MA Reverse Cylinder
Transmission Ratios
TZ250 RD400 RD250/350
.81 .888 .785
.87 .961 .888
.96 1.083 1.040
1.13 1.318 1.318
1.42 1.778 1.778
1.93 2.571 2.571
Primary Gears
RD250 68/21 3.238
RD350/400/LC/RZ 66/21 2.869
TZ250 77/23 3.35
TZ350 74/25 2.96
Cylinder Studs
RD 250 90116-08065-00 90mm(72-73mm sticks out of casing)
RD350 90116-08064-00 97mm (80-81mm sticks out of casing)
RD 400 90116-08232-00 117mm (98mm sticks out of casing)
TZ250 90116-08213-00 94mm
TZ350 90116-08212-00 101mm
TZ750 90116-08212-00 101mm
RD250LC/RD350LC 90116-08219-00 106mm
Thanks Ed, Its a comprehensive post, shall bookmark it for reference.
Hey Guys This collection of information was a bit o work so to make sure the information doesn't get lost and stays easily accessible I put it up on my website so it's there if you need it, I keep adding to it too.. http://erlenbachracing.co/RD_TZ_LC_RZ_history_and_differences.htm
Ed
I turned this into a WORD file, if anyone's interested.
Rob
Great information; I thought I was seeing things in the barn, but the RD350LC shift drum IS shorter than the RZ/Banshee item, and for a reason. Thanks EE :like:
Yamaha 90116-08232 works for the RD to LC cylinder studs. They're 116mm long, but come in way cheaper and they're common for US buyers ($6 ea). They cross reference with Banshee, RZ350, RZ250, RD (all), XS650, XS1, XS2, R5, R5B, R5C, TD3, RT360, DS7, TX750, TX650, TZ750, YZ80, YZ60
This is a wonderful thread, and I thank you guys for putting it together.
Primary ratio RD350/400/LC/RZ 66/21 2.869....its 66/23 right ?
Quote from: 2t Fan on October 20, 2021, 12:34:50 PM
Primary ratio RD350/400/LC/RZ 66/21 2.869....its 66/23 right ?
Yes, the "21" is probably just a typo. The listed ratio is correct, 2.870 (rounded)
List of primary gears:
19T RD60, RD125
16T RD200
21T DS7, RD250
23T R5, RD350, RD400, RD350LC, RZ350
I picked up a nice 69 r3. Will R5 or RD cylinders fit? I'm assuming pistons too👍