Motorcycle Repair: high idle, yamaha maxim 650, intake leak

Question
Hi Mark,
I have a 1980 Yamaha Maxim 650.  It starts fine, and initially idles around 1500 rpm.  As the engine warms up, the idle gradually climbs to about 3000rpm.  As soon as I engage a gear it drops back down to where it should be, but any time I pull in the clutch or go into neutral it revs up again.

Turning the bike off and on again reduces the idle to 1500, but it climbs back up after a few seconds.

What do you think the problem is?

Thanks a lot!
Dave
placebo ^at^ interchange.ubc.ca

Answer
Hi Dave,

I suspect one of the following:

Throttle/choke cable binding or inproperly routed.
Idle adjustment screw set too high.
Carburetor synchronization not balanced.
Air intake leak.

Send me an email address as requested. I'll return repair and test info files that may assist you.

Respectfully,
Mark Shively