After a few years of shelving my 76 RD project, I decided to dive back in. I posted here quite a bit back in 2020/2022 and got a lot of great advice. Unfortunately, life got in the way and I had to hit the pause button.
Bored one size over to 65.5mm
Aftermarket expansion chambers
New coils
Timing set 2.1mm btodc
RD350 y-boot with k&n filter
New points and condenser
Carbs:
Brass ball removed and air jet drilled 2mm
5DP7 needles one notch below center
169p2 needle jets
32.5 pilots
210 mains
Pilot air screw turned 1.25 turns from seated
I cannot get this thing to rev out. �It's decent on the low end, with some hesitation from a stop. The big problem is on the top end. From 3/4 to full throttle, it hesitates to accelerate. I can back off the throttle and feather it to increase the RPM, but it tops out well before it should. Probably 5000 in 6th gear. Lower gears are much better, but not nearly the power the bike should have.
Without a load, the motor revs up just fine to 9k.
I've tried 310, 220, 210, and 250 mains. Compression is good and leakdown test was good. No leaks in the intake. Floats are good and height is set correctly.
I'm not sure where to go from here. I can order some smaller mains or different needle jets. I'm just not sure which direction to go.
Thanks in advance!
I was wrong about the timing. The rh cylinder was off quite a bit. I must not have recheckdd after fixing some carb problems. It's set now and the problem remains.
Actually, it seems sluggish all the way through, now, with a lot more sputtering.
few qs.
what coils? are you sure they are getting over 11v when revved up?
the carbs, did you pull the jet tubes and verify they are clean?
can you try a 190 main jet?
Coils are from Economy (with ballast resistor bypassed)
Jet tubes have been cleaned, recleaned, cleaned again.
I don't have any 190 mains.
The smallest mains I have are 200. I can try those and check the coil voltage when I have another opportunity. I've been test and tuning between rain storms.