I picked up a project 75 RD350 that was sitting in an airplane hanger along with 15 vintage Hondas (Nice bikes, but took home the Yamaha). Upon getting it home and dropping in a new battery, cleaning the carbs, I had no spark. I removed the gas tank and someone had an aftermarket set on EMGO coils on it. These tested good resistance wise but I replaced with a known set of working RD350 factory coils, a new condensor and a good set of known working points that were removed when I put a dyna ignition on my 73. After timing 1.8 degrees BTDC and setting gap to .014", the bike fired up on the second kick and ran, but not well as fuel was leaking from the float bowls so I shut it down after about 30 seconds I did not do much with this until my Vermont registration came thru, then I started to tear into it. A leakdown test of both cylinders yielded 5.5 psig after 6 minutes from each cylinder, I rebuilt both carbs with a Keyser kit, installed new fuel lines and glass filters, removed the baffles and cleansed and ran the bike from an auxillary gas tank until my petcock rebuild kit comes in. The bike runs the first kick but I have raw gas coming from the right exhaust and very little if any smoke. I shut the bike down, removed plugs and each has spark, swapped plugs left to right and reinstalled, same issue. For shits and giggles, I swapped the coils and have the same issue. With plugs removed, I have a crisp spark from each plug but once installed and under load, the right cylinder seems as if it is not firing as it is cold at the head-pipe (when checked against the left) and oily gas coming from the right muffler. I have a timing light and I can put it on the right coil to verify working but as it works with plugs removed from bike, I don't think this is the issue. Thinking may be extremely gas fouled and may have to remove baffles and kick the hell out of it with clear the chambers. I even put-in new NGK plugs, no difference. Any suggestions. Thanks in Advance. Brian
Compression? Otherwise most guys don't like the Keyster rebuild kits. Are you sure that side isn't still having float valve leaks?
That's all I got...
I didn't measure the compression as it passed the leak down test but it has "considerable" compression when buttoned up with a spark plug.
I was also told that Keyster is packaged by Sudco in Japan from the Retro cycle store in Seattle. When I opened the bag it had Sudco printed on the packaging.
I don't have much experience with Keyster, just letting you know what I've heard.
Compression has nothing to do with leak down in a 2t. Comp is how healthy your rings and piston are. Leak down is making sure your seals, etc are good.
:vroom:
I think you've eliminated ignition-related causes and a bottom end full of raw fuel seems likely. No easy way to clear it out that I know of. More kicking or waiting...
Does choke make any difference?
I had it on initially to get started then turned it off after ~10 seconds. Will kick thru with fuel disconnected and then see if I can get it to fire after purging. Might go with another set of new plugs also to take any concern of fuel fouled plugs out of the equation
take plug out of offending cyl, move plug wire out of way, run it on good cyl. with plug out ofRH for a few seconds, will clear our flooded cyl. Id suspect the petcock is seeping and flooding cyl when sitting.
I ran some more tests today. I reset the timing using a dial indicator set to .079" (2 mm BTDC), used my meter to verify the points are opening within .0005" of this setpoint, set points a little tighter to .013" and had same issue of only running on left cylinder. I was thinking about 'what changed' and I had rebuilt the carbs previously so I put the OEM components back in (needles/jets/etc.) with the new gaskets and started the bike. The bike is still running on the left cylinder afterwards. I removed the right plug and ran the bike for 15 to 20 seconds on the left cylinder with a rag over the open spark plug hole to purge, reinstalled the plug and the same issue, only running on left cylinder. I do not have my factory gas tank hooked up but an auxillary gas tank with a shutoff. I decided to remove the right exhaust and I poured raw fuel and oil from the muffler when removing (roughly 4 to 5 ounces) and then removed the baffle and poured out some more. I reinstalled the muffler/baffle as I now know that the issue is fuel related and not spark , compression or timing. As the fuel in the float bowls was running out while attempting to run this again, the mixture became leaner and the fuel in the crankcase began to light off, (right cylinder was firing intermittently) I am wondering how fouled the crankcase is, so I left the bike to sit with both exhausts off and the spark plugs removed. Gonna have to wait until next weekend before I can play again, hopefully in this amount of time the crankcase will dry out and then I can reinstall mufflers and try again.
yup/ thats pretty telling. go kick it over every once in a while over the next week if you can as well.
look at petcock.
At it again, muffler and plug were removed for a week, kicked thru a few times in between. I removed both carbs, rechecked the float levels (15 mm, used a gauge block to get as precise as possible). Floats are not damaged and float guide pins, straight with no burnished or spots that would drag on float. Inverted carbs and blew thru fuel hose, did not flow as needle and seat are functioning. Carbs reattached along with muffler. Inserted Brand new NOS NGK B8HS plugs (gapped to .026") checked these for spark before inserting in head. Used a small dab of copper anti-seize on threads before insertion. Bike fired on left cylinder and then after about 30 seconds, the right cylinder fired and ran really rough until the bike stalled roughly 30 seconds later. I attempted to kick over again and only ran on left cylinder. Swapped plugs left to right, same issue. Removed muffler and poured raw fuel from. I started the bike with muffler off of right side, did not fire on right cylinder,only ran on left. Removed right cylinder spark plug and ran bike for 45 seconds on left cylinder at idle only. Shut off bike, installed coil wire to plug and ran bike with plug removed on right cylinder laying against the head. Plenty of spark visible. Reinstalled everything and only firing on left cylinder. Turned off petcock and wheeled in garage. Pretty frustrating, thinking if a damaged reedset would cause this? Any other suggestion? Thanks Brian
sounds like petcock is seeping, thru the carb, filling cyl then pipe. nothing to do with reeds, it's flooding sitting
While it's parked, disconnect fuel line and run a line from petcock to a pan on the floor and see if it leaks over time
The bike sat all week with the fuel tank off. I was running an auxillary tank (with a shutoff) in the previous tests and had all gas tanks disconnected for an entire week with the exhaust and plugs out- in whic=h I kicked it thru a few times. I rebuilt the petcock of OEM tank this week prior to installing on bike and running today, being careful to turn on and off the gas flow until the bike was ready to be run. In my 30+ years of working on bikes, never had this much trouble. Really stumped
as you foul the plug its still not pumped all the fuel out. I've never seen raw fuel accumulate that fast with out the crankcases being full. that being said, swap carbs left to right, cap off choke crossover see if it follows the carb.
following this closely as I'm having a similar issue.
Make sure your slides are in correctly, cut outs facing the rear of the of the carbs/bike. I know it seems silly but I've seen it many times.
So as I was working on the 72 R5 this weekend, this thread came to mind.
I took the LH carb off to adjust the float level and also look at the pilot jet to write down what size i had in there.
In the middle of this, I got distracted with a ph call, then got back into it.
After getting the carb back on, i fired it back up and then all of a sudden had the -exact same issues- as the OP stated.
after a few minutes i looked and lo and behold, the pilot jet was sitting on the workbench. :taz: so, i put it back in and was idling OK again. but it pissed out a bunch of fuel out of the pipe. :shuddap:
Then, it had me thinking way back, i was helping soembody with a GT750, and he had fit VM34's to it, was very modified.
when we got to tuning, he had rejetted the carbs ad had the exact same issue. this was like 18 yrs ago, but i distintly rememebr, when we pulled it apart, the pilot jets were the mikuni 4 stroke variety.
In this, it means that the metered orifice is at the pointy end, not near the threaded portion and will run dead rich but otherwise look 'similar', be numbered the same, etc. when we took the carbs off i noticed the lack of emulsion holes and there it was.
Just 2 things to look out for.
:twocents:
('incorrect' pilot below)
I have been working alot to make some numbers for year end and have not had time to work on the bike. Should have this weekend to get sorted, plus it has been sitting awhile to dry out any unspent fuel in the crankcase
Had a break from work and got the bike running today on both cylinders. I think it was extremely gas fouled and it sat for 2+ weeks, kicked thru every few days. Both cylinders are running good, even temps on each (non scientific-back of hand measure). Idles well and seems to be sorted. Fires first kick. Appreciate all of the input and support.
Thanks, Brian
:clap: