RD350 Project Mustakrakish

[bostontrackrat]

Long time, no update.

Still plugging away slowly on the wiring harness.  I bought a nice new soldering workstation to make things go a little smoother, and I sent the jugs off to PowerSeal USA to get bored and nikaseal coated.   Just waiting to get those back so I can make the next big jump forward with engine assembly.

In the meantime, I took the wheels over to my friends at Nova Motorcycles to get a fresh set of BT46 tires!






OH!!!!!!!!   And I got my shiny new green license plate from the wonderful State of Vermont! 

[NoRiders]

Good progress. What plans do you have for the spokes?

[rodneya]

Your rear wheel has balancing weights on almost opposite sides. Kinda defeats the purpose of adding weights.

[bostontrackrat]

Good progress. What plans do you have for the spokes?

Live with them for now and putt around this summer without hustling the bike too much.   Next winter vapor blast the hubs, polish the hoops, and get new spokes from Buchanan's. (maybe even excel hoops if I'm feeling spendy  ).

Your rear wheel has balancing weights on almost opposite sides. Kinda defeats the purpose of adding weights.

Interesting, I didnt even see that when I bought them home.  Thanks for catching that.  I'll redo it later.

[bostontrackrat]

I swear I didnt abandon this project!

I havent updated in awhile because I've been busy getting the Honda Hawk GT up and ready for track season, and I had a couple of trackdays which took up my weekends.  At the last track day I had a nasty highside crash while rolling on too much throttle while still leaned over hard in the corner.   Nothing broken, but sore and it's taken me a week to get to the point where I can move around enough to work again.   I got the Hawk mostly fixed up and I'm waiting on some new parts to arrive in the mail, so now I have some bandwidth to get back to the RD350.  Tonight I worked on top end assembly a bit.

I'm working with Wiseco banshee pistons here, so I used the dremel to flatten down the center tang, and then made it nice and smooth with sandpaper.  I also went all around the piston's edges with sandpaper to make sure there were no burrs from manufacturing.


I placed the rings into the bores and measured the ring gap (i had plenty), and then got everything ready for assembly.


I lost my brand new set of wrist pins, clips, and small end bearings that came with the pistons.   So I ordered new wiseco bearings from Economy Cycle, and decided to reuse the wrist pins and clips since they looked to be in decent shape.


Pistons all installed, getting excited now!


I learned to work on engines from my dad on old american cars, and he was a big believer in the Permatex red hi-tack gasket spray.  We've always had good luck with it, so I figured I'd try it here.  But this is my first 2 stroke so who knows.  Do any of you guys use this in your engines?


Cylinders slide right over nicely.  I made sure to double check that the rings were lined up with their retaining pins.


Oh boy, was this a sight for sore eyes.  That actually looks like an engine!  I only put the heads on there and put two bolts in there lightly to apply a little pressure to the base gasket while that high-tack cures.   I'll remove them tomorrow and put the copper gaskets in the top end.   I didnt do that just yet because I had one or two of the head bolts that didnt want to thread on correctly.  Do you guys just reuse the old ones indefinitely?  Or do you try to use fresh ones (assuming the threads stretch and mess up your torque specs like they do on cars)?   Is there even a source for getting new ones?  I havent seen them anywhere online.

[bostontrackrat]

More progress last night 

I prepped up the Vape ignition for install.  I followed all the advise in Chuck's thread on it over in the Team Scream section.

Busting out the RTX (black and decker's Dremel knock off) and got to work.


Beveled all the edges for clearance and to protect the wires.


After that it was still rocking back and forth when installed because it was high centering in the middle.  So I carefully ground down some material around the seal.


Lastly, I added RTV to prevent rubbing and vibration on the wires.


Thanks to Chuck at Team Scream for sharing his awesome knowledge and experience to everyone on the forum.

I've got a wild idea here,  if I keep making good progress on this, I may try to have the whole bike together in time for USCRA next weekend!  (I wouldnt place money on it though)

[bostontrackrat]

Notes on my Vape install:   I drilled the 2 additional holes in the backing plate as Chuck suggested and tapped them for more screws, and somehow completely screwed up the alignment with the magneto plate, it's not even close.    No idea how I messed it up so bad.   So that will be a project for a later date.   In the mean time, the 2 existing bolts are installed with a healthy amount of Red locktite.    Today, I'll make sure the three coil retaining bolts do not stick out on the back side by either using washers or sanding them down, and they'll get installed with blue locktite.

[bostontrackrat]

Got the bolts sanded down so they dont stick out the back, and routed the wires.  Also rigged up a neutral light cable at the same time.   Realized I'm missing the bolts to mount the back plate to the engine cases, so I need to run to Home Depot tomorrow.

[350GUY]

For a LONG time, I've been dreading the ignition part of the equation.  I'm not afraid of wiring or electrics, I understand them well, but it was probably going to be one of the biggest ticket items on the project, and my wallet has taken enough abuse already.  I was cross shopping the MZB/Powerdynamo/Vape system with the HCI.  I was leaning heavily towards the HCI system because I'm not going to have a heavy electrical load on this bike (Literally just headlight and tail light), and I liked that it was going to save me over a hundred dollars.  Well as luck would have it, one morning 2 weeks ago, I searched facebook marketplace for "RD350" as I do every morning while having coffee, and some guy down in CT had posted a pile of RD350 parts left over from his last build for 75 dollars.   In the box, no word of a lie, was a complete Vape system!   I met up with the guy the next day to pick it up, super nice dude.  We chatted bike for a bit, and he said he pulled the system off a fully running RD, so he knows it works, and it only had a few hours on it.  He's just getting out of RD's right now, and trying to get into an RZ350. 

So here's the loot.





This next part beggars belief.  You see in that picture how there was an ignition switch with a set of keys?   The little key was a match to the steering lock and seat latch on my original bike that didnt come with any keys!  What are the odds of that?

Lady luck did shine on you!
Thank you for the excellent progress report. Great job.

[pdxjim]

I lost my brand new set of wrist pins, clips, and small end bearings that came with the pistons.   So I ordered new wiseco bearings from Economy Cycle, and decided to reuse the wrist pins and clips since they looked to be in decent shape.


Pistons all installed, getting excited now!


I learned to work on engines from my dad on old american cars, and he was a big believer in the Permatex red hi-tack gasket spray.  We've always had good luck with it, so I figured I'd try it here.  But this is my first 2 stroke so who knows.  Do any of you guys use this in your engines?

I wouldn't recommend reusing wristpins/bearings, and especially not circlips.

Most of us just grease or oil the base gaskets for ease of disassembly.  Cylinder base is a low pressure joint, so no adhesive or sealer is needed.

[Dvsrd]

Back to project at hand.

Now at home in quarantine, I have to get more creative.

I made a truing stand for the crankshaft out of some angle iron.
Note: After this picture I realized I was an idiot and needed to have the stand rest on the outer bearings to get a proper reading

First of all, you're doing a great job with your RD. Not to mention your Hawk Love those bikes!

However,  I have a comment on truing of twin cranks. I have attempted truing between deadl centers in a lathe, with mixed results.
IMHO,  the best setup for truing an RD or TZ crank is V-blocks under the two inner bearings, and the dial gauge(s) on the outer bearing surfaces, no bearings fitted. Only that way you confirm 100% that all 4 bearings share the same centerline.

In fact, I once saw a pic of the late Jarno Saarinen checking out runout on a TZ crank, using a piston as v-blocks. Just a normal TZ pistol, upside doen in a vise.

[bostontrackrat]

Thanks for the feedback guys! It's greatly appreciated! 

I hear you about not reusing the wrist pins and clips.  It's together now, and I'm gonna roll the dice a little here, and try to enjoy it for the short little bit of the season that's left here in New England before the cold comes.     This winter I plan to blow the bike back apart for numerous upgrades (vapor blasting cases, paint, RD400 transmission, new clutch plates, rebuilt crank, ect), and I'll do fresh piston pins/clips/bearings then.

Made some good progress last night.  I went to home depot and got some new M5 countersink machine screws to bolt the back plate to the engine cases.  These went in with a HEALTHY amount of blue Locktite.


Immediately after this I brought a piston to TDC and backed it off as best I could to 1.8mm BTDC.  Then I went to mount up the rotor and gave it a gentle love tap with the deadblow to seat it on the crank taper...... and it didnt stay there!   I lined it up again and give a little bit more of a whack......... still didnt seat right.  I could pull it off by hand.   Cool.

So I took everything back off, cleaned off all the locktite I just did, and busted out the valve grinding compound.   Time to start lapping.


After lapping the rotor to the crank for a WHILE, and cleaning it very diligently with paper towels and brake clean I lined everything back up where I wanted it in respect to timing.... placed the rotor just so.... gentle whack with the deadblow and.........  that sucker is ON there!    I pried and pulled on it as best I could by hand and it would not come lose.   Satisfied that I had a good fit I put the rotor bolt in (Economy Cycle upgraded set) with a good dollop of blue Locktite, and torqued it down to 165 in-lbs, and called it a night.

[dgorms]

Boston, every time I have used something to "get me by" it F'n blew up right before I got back to it! Just speaking from 40 plus years of "DUH"............................................D

[Economy Cycle John]

Looks good, that's one of the older riveted drums with the square triggers that can cause the engine to start in the wrong direction, and those rivets were known to loosen up over time. They changed the drums several years ago to a one piece cnc drum with ramped triggers.
John
EC

https://www.economycycle.com/shop/yamaha-rd250350400r5ds6ds7-parts/electrical-ignitions-lighting/ignition/mzb-rotor-updated-design/

[toffee]

Great thread!
I too am fitting a VAPE Powerdynamo ignition at the moment, I wasnt aware of the mods which people are doing,
I gonna check them out.