250r issues-starter kicking back, pipe blowing off???

[newrider3]

So apparently I'm not cool enough for you guys to reply to any of my other threads, but maybe you could help me with my latest problem; I'm completely stumped as to what is going on and would really appreciate some help.

I've been having issues with getting my '86 250r running properly lately. It was jetted very rich to start with, it started first kick, and ran nicely with some tending of the throttle (but smoked more than you would believe). After setting the float and needle where they should've been in the first place, and dropping the jets a couple sizes, it ran well, idled nicely, little smoke. I was riding it around, trying to unstick the clutch, when it stalled (I mis-shifted) and we couldn't get it to start again. Sometimes the kicker would try to 'kick back' and break my ankle, and sometimes it would seem to misfire and blow the expansion chamber off its springs.

So, yesterday, I put the original jets back in, and it fired up and ran, still pretty rich on the bottom end, and it wouldn't idle itself. Bumped the pilot jet down a size, and it started up nicely again, almost idled. Shut it down and started it up for short periods again a few times to make adjustments, then it wouldn't start again. Giving me the same problems with the kicker trying to kick back, and the same almost like 'backfire' inside the pipe, sort of a loud off-time pop/clunk from the exhaust, even sometimes blowing the pipe completely off the flange and out of the silencer slip-fit.

I have absolutely no idea what the problem is, the closest idea I can come up with is that the timing is off. Does this motor have a flywheel key or such that could be sheared, like on a small mower engine?
Any suggestions?? THANKS

[RodKnockRacing]

yes it has a flywheel key that could be sheared take the cover of and see if it has play in it and go from there i imagine someone else could give you more ideas

[Texas 200x]

It sounds like your cdi maybe acting up. I would think if your flywheel spun it wouldn't run right sometimes and not at all others. I would get out a timing light and see what its doing. If your spark is jumping all around its most likely the cdi.

[RodKnockRacing]

It sounds like your cdi maybe acting up. I would think if your flywheel spun it wouldn't run right sometimes and not at all others. I would get out a timing light and see what its doing. If your spark is jumping all around its most likely the cdi.

i second that

[3wheelmecca]

we should do it up this weekend. I'll get ya going.

[phil53]

My ankle is messed up from a sheared key way on my flywheel, advanced the timing causing to fire while going into kick pretty heavy, ankle turned black and blue within minutes. Definitely sounds like a sheared keyway. Rough starts can sometimes be worn reed petals.

[newrider3]

It looks like we have a winner, I took off the cover, and the flywheel pretty much spun around by hand. Not much left of the key than some shavings and a sliver of metal still in the crank keyway.
Thanks for the help, everyone.