82 GS450TXZ revving up on it's own!

[Anonymous]

When it's cold the bike idles and runs at normal revs, however, when it's warm it starts to rev up on it's own in idle and when riding it. What could it be?

[Detman101]

Dm of mD

[earlfor]

Re: 82 GS450TXZ revving up on it's own!

The carbs are running too lean in the idle circuits. Open up your mixture screws.

Earl

When it's cold the bike idles and runs at normal revs, however, when it's warm it starts to rev up on it's own in idle and when riding it. What could it be?

[Anonymous]

Re: 82 GS450TXZ revving up on it's own!

The carbs are running too lean in the idle circuits. Open up your mixture screws.

Earl

When it's cold the bike idles and runs at normal revs, however, when it's warm it starts to rev up on it's own in idle and when riding it. What could it be?

That would be anti-clockwise, correct?

[earlfor]

Re: 82 GS450TXZ revving up on it's own!

Yes, turn them out/counterclockwise. I would try 1/2 turn as a "best guess" :-)

arl

The carbs are running too lean in the idle circuits. Open up your mixture screws.

Earl

When it's cold the bike idles and runs at normal revs, however, when it's warm it starts to rev up on it's own in idle and when riding it. What could it be?

That would be anti-clockwise, correct?

[Anonymous]

Where are these screws located, I presume there is one per each carb?

[SqDancerLynn1]

The screw is on the intake side of the carb, it may be covered by a plug. If an adjustment doesn't help? Remove the carbs and change the large O ring that goes between the engine and the intake boots, examine them for cracks

[Anonymous]

I'm not seeing the screw, does anyone have a picture? I do see a flat head screw right before the rubber boot that mounts to the engine in a metal cyliner. Is that it?

[SqDancerLynn1]

Should be something similar to this

http://www.thegsresources.com/images/carbs/026_Air%20screw%20removed.jpg

[nabrams]

The mixture screw for GS450 carbs is covered by a cap that must be drilled out (be very careful not to damage the screw). I've done this for two GS450 bikes (mine and my friend's).
Personally, I don't think that is the likely problem, especially if the bike has not been sitting for a long period of time.
I think you've got a small air leak somewhere which only leans the mixture enough under certain climate conditions. It ends up leaning the mixture enough to cause a rise in RPM. When an air leak gets really bad it has the opposite effect - too lean a mixture will result in a drop in RPM. Check all boots that connect to the carb, the air box, air filter and air box lid.
If you've got a loose spark plug that allows air in under some conditions (temperature and/or humidity combinations) that could also cause the problem.
See may other post regarding air leak problems - I wasted tons of time tracking down other things when it was air leaks all along.

[Anonymous]

I'm taking it in tomorrow so a shop can look at this problem. It's been one thing after another with this bike!