[Chromer]

What would cause the bike to idle fast for no apparent reason. It did it the other night for about an hour until I quit riding, then again the next morning for about an hour before it settled down and started idling normally. The idle adjustment on the left side of the engine had no effect.

Thanks!

 

[Verrice]

Is it doing this only when you first start it or after it's been running awhile?

The bike automatically runs faster when it's cold (automatic fuel enrichment instead of a choke).

 

[Chromer]

After it's been running a while. I haven't done the ground fix yet. I'm thinking this might have something to do with it. I just had the dealer service it 600 miles ago.

 

[Verrice]

I would think a bad ground would cause the opposite (lack of spark causing uneven or low idle). Perhaps your throttle cable is sticking? Does it feel smooth and fluid? Can you hear the butterflies snapping shut when you let go of the throttle? Maybe take off the air cleaner and try various types of throttle movement (slow, fast, snapping closed, etc) and see if anything hanges up.

 

[Chromer]

If it were the throttle cable, wouldn't the idle adjustment still make some sort of difference. The idle adjustment had no effect during the fast idle episode.

 

[Verrice]

Not necessarily... it depends on how / where it's sticking. Does it ever accellerate on it's own or is the high idle only after a decelleration?

 

[Chromer]

Oh, and thanks for the suggestion. I'll check the throttle linkage but I'm sure it's not sticking. It feels as free as could be.

 

[Bareass172]

I suppose it could be your wax valve... This is what adjusts idle at cold temps, and given it's a simple mechanical valve I can't see how it would go bad, but... :?

 

[Chromer]

I noticed it mostly during idle but come to think of it, it might have been a little harder to shift like it wasn't idling down after the clutch was disengaged while riding.

 

[Verrice]

Something you could try as a test, without disassembly, is the next time it's like that in idle, give the throttle a good snap. Let it get some momentum behind closing. If the fast idle stops, it was probably a stuck throttle, if the fast idle continues it still could be a stuck throttle, but I'd start thinking of other possibilities.

Don't know enough about Bare's wax valve to go into that.

 

[Chromer]

Thanks for the help guys. Next time it does it (if it does it), I'll check out a few things. Seems like it is something other than the throttle though. I did try to snap the throttle to make it stop with no effect. Could it be starved for air? I live in Wa. state and do get caught in the rain on occasion. (Most people who ride here do.) It wasn't raining at the time but I did get caught in it a day or two earlier. Maybe it was trying to compensate by idling fast so it could breath?

 

[RobDogg]

There have been some RARE instances of the wax valve going bad. If it does it again or starts doing it all the time, you could have it checked out. It's a mechanical valve and it could cause the symptoms you mentioned (no change with the idle adjustment)

But if it doesn't happen again, no worries. 8)

 

[SixFTMoose]

Mine was doing the same thing last summer and I found a vacum leak, one of my vacum lines had a crack in it. Worth checking out.