81 gs450rebuild-another gs forum success -almost - sticks at 4000 rpm

[Guest]

Rebuilt my sons all stock 81 gs 450 ignition system with dsc-3 and coil relay mod. Also put new intake manifolds and or O rings on carbs when cleaned them. Got the bike running better then ever has, ...almost. Now have a high sticking idle, approx 4000 rpm when riding. Good power thruout rpm range accelerating but will not drop back down to idle unless shift down to first gear and let clutch out slightly to put drag on motor-then will drop to idle. Other higher gears, 2nd 3rd will not bring it down. Once stopped and revvin away -If turn off bike and restart immediately - will go back to idle at 1050. Any ideas?? Also, Its not the throttle cable -appears to not be hanging up. Im at a loss. And now that its runnin he wants to ride it as is and he's a novice- his first bike. Hopin to get it sorted out soon. greg

[tom203]

So you put new o-rings at carb boot/ head interface? Is "choke" fully off?

[gs rider]

yes, new o rings at boot/head interface. I saw another post during a search about a possible petcock issue causing high idle ? I recently had this petcock apart to clean. Perhaps i didnt put it back together correctly??

[gs rider]

tom based on your feedback i checked choke- tightened it up some in event is was slipping open. Then tightened up my throttle cable some. I think that did it. Now has more tension to pull slides down and throttle feels like used to. no more hanging up at 4000 rpm. I never opened the back/vacuem part of petcock but if happens again- thats my next try. greg