Motorcycle Repair: 81 Honda GL 1100 Goldwing, honda gl1100, honda gl

Question
I have recently acquired a chopped 1981 Honda GL1100 Goldwing, My problem is: engine will not idle smoothly. When the throttle is applied, just enough to keep it running, the engine will rev high & slowly drop & I can't adjust the idle set screw enough to find a happy medium. I've sprayed starter fluid around the intake & it does respond as if there is an intake leak, however I can't isolate if it's the boot seal or around the sinchronizing linkages or both. Am I on the right track?

Answer
Carey, your problem could be a couple of things.  The first thing I'd do is check compression.  If the compression is low, it will take more throttle just to keep the bike running and so it will be unstable because as the speed picks up there's less compression leakage and the engine revs up.

Assuming that not the problem. Take a look at the timing advance unit.  A lot of times the springs will relax a little allowing the timing to advance too early.  That can cause the symptoms you describe.

Lastly, you could have a carburation problem as you suspected.  It could be caused by a plugged idle jet in one of the carbs or an air leak.  The most likely point for the air leak is around the intake manifold boots.  A simple tightening of the clamp normally fixes that problem.  I wouldn't think the throttle shafts would allow enough air to leak in to cause this problem.  If you can feel slop in the shafts, they are worn out but this would only happen on a bike with a lot of miles on it.  Like over 100K or more.  I've never seen the carbs wear out before even on high mileage bikes, but I suppose it still possible,

Good luck
Rich