Acceleration hesitation

[FreuderLocks]

Hey all,

Ive been having a problem with my 81 GS and im not sure of the cause of it is. The bike tends to hesitate when I roll on the throttle, Since my tach is currently not working I would estimate that it hangs back between 2,000 and 3,000 rmp and then its fine. Im thinking I either need a carb tune or clean. In the case of a cleaning, can I spray carb cleaner in the carbs and use that as a first step in rectifying the problem?

The bike doesnt smoke
Starts fine
rides fine other than hesitating.

Thanks in advance all!
-Paul

[Billy Ricks]

Spraying through the carbs won't do much but if you get the small jets at the mouth of the carb you might clear out the pilot jet passages a little. The rpm range you're describing is where it's transitioning between the pilots and slide needles. If you're good on the rest of the needle up to about 3/4 throttle then I would suspect dirty pilot circuits, maybe synch, and or pilot screws needing adjustment.

When was the last time valves were adjusted?

[Steve]

How far back do you know the history on this bike? Is this bike new to you, or have you had it a while and this is a new problem?

Either way, it sounds like the needle jets and/or main jets are not flowing as well as they should. They need to be cleaned.

Can you spray carb cleaner in as a first step? Certainly.
Will it do any good? No.
Spraying carb cleaner will only clean the areas where air flows through. Your problem is where gas flows through. You might see some improvement by running some Seafoam in the gas for a couple of tankfuls. Rn it about twice the recommended dose. Add some to your tank, fill up the tank, go for a ride. Go through most of the tank, then let it sit overnight. Fill the tank with another double dose of Seafoam and go for another ride. This time, when you come back, add gas only to the tank and ride it long enough to get it through the carbs, then park it. While the concentrated cleaner mix is good for cleaning, I'm not su sure that it's good to leave in thee for much longer than overnight.

.

[Dave8338]

Steve...I let Seafoam sit (heavy dose 2+) with Staybil in the carbs all winter, never drain the bowels and have never had a problem.

This assumes that the carb(s) are clean to start with...