Idle rising?

[Guest]

I'm sure that there is a simple answer to this that I just don't see. The bike is a 1981 GS 450 L. The problem, when she is started with the choke, she settles down to a nice 1100 rpm idle. After riding about 2 or 3 miles she idles at about 14-1500 rpm. She goes to work with me 6 days a week, 8 miles one way. The ridie to work is about 3 miles stop and go traffic to about 5 miles on the freeway. Other than the idle speed she runs perfectly.

The Carb boot O rings were changed at about 14500 miles. She now has 18000 miles.

Any thoughts?

[BikeNut]

My first thought would be an air leak. Have you tried spraying the air boots and surrounding area with parts cleaner and listening for a change in rpm? If you turn down the idle screw, what happens?

[Guest]

In the stop and go traffic your bike is getting hot which raises the idle. You might want to richen your pilot circuit a bit to cool down your bike at idle.

[Guest]

No air leaks...that was my first thought. I'm afraid to set it for stop and go traffic because I ride her in a real mix of conditions daily; though that does sound like the cause of my problem.

[Guest]

I bought an oil cooler but I live in a high heat area. I used to cruise around Fort Pitts on a Kawa LTD 1000. Worked downtown and got away with parking at an old abandoned gas station for free avoiding the nasty parking fees:-\" After highway riding does it idle high?

[Road_Clam]

No air leaks...that was my first thought. I'm afraid to set it for stop and go traffic because I ride her in a real mix of conditions daily; though that does sound like the cause of my problem.

Increasing idle is almost always an air leak somewhere. If your air screws were set too lean, your engine would stumble upon takeoff.

[Guest]

No stumble...I guess I'll check for leaks again...

[Dave8338]

I used the WD-40 trick to try locate any leaks (drop in idle speed) and was unable to find any...then (though slightly more risky) I went with the starting fluid and the spray tip from the WD-40 with the straw in place and had instant success. Idle will increase with starting fluid. Found my leaks at the head where the intake o-rings are. New o-rings and the problem was solved.

[tconroy]

No stumble...I guess I'll check for leaks again...

It is hard to get to but try to bend your nozzle on the wd 40 around the backside of the intake boot where it meets the cylinder head.That will tell you if it is your 0-rings which it probably is if you havent changed them in the past 10 years.There only 4 bucks a piece and thats better than burning your valves up.

[Dave8338]

tconroy good to hear from you...thanks again 750 miles later what a ride!

Now back to our previously scheduled programming......

[tconroy]

tconroy good to hear from you...thanks again 750 miles later what a ride!

Now back to our previously scheduled programming......

I was kinda wondering how it was going. Sounds like it's going just fine. glad to hear that!!!!

[Guest]

It is hard to get to but try to bend your nozzle on the wd 40 around the backside of the intake boot where it meets the cylinder head.That will tell you if it is your 0-rings which it probably is if you havent changed them in the past 10 years.There only 4 bucks a piece and thats better than burning your valves up.

That's why I doubt the O rings are the problem...I changed them last year.

[tconroy]

That's why I doubt the O rings are the problem...I changed them last year.

Throttle cable look ok?Are your boot clamps snug? Choke cable look ok. Choke rail hanging up? Just kickin out afew ideas.