Tornado
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- Joined
- Dec 5, 2017
- Messages
- 4,855
Have you checked the tank vent hole in the cap and the petcock mesh screens for fouling, giving a fuel starvation issue at max demand?Thanks for checking, I have been a little slow on reporting progress.
I swapped out the stator and magnetic pick-up with a replacement unit that I have. Set the air gaps with the original reluctor. Set static timing at 28*. Strobed timing. Similar performance as before: 21* indicated at 2000rpm and 40 ish at 5000rpm. Not jumping around as much though. Retarded static timing to 15*. It now strobes 30* at 5000+rpm. Left it set there. Road test showed that rpm kept increasing past 4500 in 4th gear. Couldn't go past 5000rpm because of traffic.
I buttoned everything up with the modern replacement RITA electronics (Rexs), replacement stator and original reluctor.
Conclusion: I believe there were 2 issues. First, the Mistral RITA set up instructions result in way too much advance at higher rpms. This was easily resolved by setting up for the correct advance at high rpm, as was suggested by some folks earlier in the thread. The other is that it appears there was a problem with the original RITA stator & magnetic pick-up assembly that caused quite a bit of jitter at high rpms.
However, while the 4th gear performance is better than before, I still feel that it may be less than what I experience with my stock 71 750 Roadster. There is the difference in 21 vs 20 tooth sprocket, but come on man, this is supposed to be a Combat!
Now that I feel the ignition timing is ok, I have moved to carburation. The bike has 32mm Amal Mk II carbs jetted same as called for MK I on Combat engine. A WOT roll-off test indicated that it was lean. I swapped the 230 mains for 240 and there is now no surge on roll-off, but I also sense no difference when the throttle is moved from above 3/4 to fully open.
That is where I am now. I am going to try different needle positions. It is currently on center position. I'm going to move them 1 notch richer. I realize that shouldn't affect the WOT performance, but that is the next thing I can experiment with.