I'm just about to kill myself over this damm thing.
I got my '91 400 about 4 years ago. It had a cracked stator cover and I was too cheap (poor?) to pay for a brand new one. It took over a year but I finally found one cheap. Unfortunately, it sat outside under a cover for the whole time too. So after replacing the cover, I discovered a myriad of issues that I've tried to address.
Drained, cleaned, and coated the tank.
Cleaned and synched carbs.
Bike was still hard to start and wouldn't run worth a crap.
Replaced fuel petcock with brand new OEM part.
Recleaned and synched carbs.
New plugs.
New chain, front fender, and fork seals.
Better so I tried to ride it a good distance only to have it die on me. Dead battery.
Output voltage to the battery was low. Cleaned terminals and harness plugs - which were all very corroded. Charging voltage is now perfect and hasn't been a problem since.
Tried to take bike for another ride. Started decently, idled well, but power/fuelling was very inconsistent. Bike did not want to pull above 7K rpm and eventually quit running and refused to restart after about 10-15 miles. Let the bike sit for several hours or overnight and would immediately restart.
Resistance test of coils indicated they were ok. This left either the signal generator or the CDI box. Given the history of CDI failures, I had the box repaired per the instructions from this website. Shop that did the work said the components that it replaced were definitely bad so I had high hopes.
Installed the repaired CDI and now it starts much easier and power is noticeably smoother although still flat on the bottom (even for a high-strung 400) and the rev limiter (at least I think it's the limiter) kicks in around 12K, 2K short of the indicated redline. The big issue though is that it still dies and will refuse to restart. One seemingly minor difference is that it will run longer/further than previously before it dies and may be happening after a bit of a short blast up the rpm/power/speed curve. I can drive it around the neighborhood all day.
I've done all the usual checks for venting and there's nothing (no sound from the fuel cap when opened, no pinched hoses, etc.) to indicated a problem there. I did discover that, on one ride, at least one plug boot was loose. (There may have been more than one - I don't remember.) Secured the boot but the problem still persisted.
At this point, I'm thinking either the coils are heating up, the signal generator is screwing up, or there are more corrosion/connection issues in the harness. I'm leaning towards the coils.
I really like this bike but I want rid of it. It's brought me damm near to tears too many times. However, I don't want to take a big hit on it because it won't run properly. Plus I don't want to lose. I want to finally figure this thing out.
So if anyone has any input on the situation, I'm very open to suggestions. Or purchase offers.
Topic: At the end of my rope (Read 2615 times)