I installed the BB TM34 I've had sitting in a box for four months today. Bike starts up fine, but once it warms up it idles a bit funny. It will idle at about 2000 RPM, then after a minute or two it'll drop down around 1300 and stumble a bit like it wants to die, but doesn't. Minute or two later it pops back up to 2000, and the process repeats.

If I blip the gas, it'll come back down to 2000 and sit there for about a minute before dropping to 1300-ish and then start the same thing. I vaguely seem to recall the last TM34 I had doing the same thing, but it's been like two years so I don't remember very well.

But it's almost as if it's loading up on fuel causing it to bog a bit, then leans out and idles higher. This is with the choke off btw. But if I give it throttle while it's idling low, it response right away.

I haven't been able to ride it yet; I just finished up 15 min ago and I can't get the bike out of the trailer til tomorrow sometime.

Rob

 

I'm thinking it's too lean. Lean idle mixture tends to high rpms in order to keep the bike from dying, then fluctuates to where it's usually set (1300rpm). I suggested enriching up the idle mixture screw.