Major Bogging & Throttle accelerating itself

[mikeygman]

I just bought a 1997 KDX220R. Everything on the bike is stock. Any time you throttle way down the bike boggs in every gear. It smokes real bad, it doesn't idle very well, and is pretty difficult to start. But the real problem is that is accelerates itself sometimes. It did it in third and 1st gear. Basically what is happing is as I am doing easy riding it starts to rev itself faster and faster, I end up having to throw in the clutch and hit the kill switch. I took the bike in for service, they said the carb was in great condition and very clean, no exhaust cloggs, power valve was clean, piston looked great. They said it might be electical. Any ideas out there?

 

[dirt bike dave]

IMO, the runaway throttle is probably a frayed throttle cable. A new one is less than $20 - make sure you route it properly.

 

[KDX200Kev]

Its sounds to me that you are running real rich. Try leaning it out as described on Cdn Daves recommendations.

 

[sick 96 250]

isnt that a sign of a possible air leak somewhere. Could be the cable is shot as well but i believe an air leak causes this also. Search around on here for reving high, air leak, etc.

 

[Mainekdxer]

Check the rubber boot that comes off of the carb and connects to the air box. Mine was having similar problems a while back and that was what it was. It was a small crack so make sure you really check it out good. Under $50.00 to replace.

 

[razrbakcrzy]

Leaning out because of an air leak will cause this or if the float sticks and causes the bike not to get enough fuel will cause this or if you just plain run the carb bowl out of fuel will cause this. "say by not turning on the petcock on and the carb uses all the fuel in the fuel bowl" It will rev out of control. My son did this to his quad not to long ago while he was attempting to adjust the carb. It was ideling and he had the petcock in the fuel position, the fuel got so low that it used all the fuel in the line and fuel bowl and reved out of control as it go leaner and leaner. if he would just have had the petcock in the reserve position it would never have happened. Let me tell you it scared the crud out of him. all I could do was laugh!!

Good luck.
Jim

 

[G. Gearloose]

Find & Fix the lean-run away...The kill switch may not work one day, as the plug cathode gets hot enough from the lean condition, the engine runs like a glow-plugged model engine, and frags your but into a tree.

 

[motodr9]

Sounds like air leak to me

 

[Fred T]

Replace the throttle cable first and see what happens.

Take it one step at a time to eliminate things. Bad cables can make the bike act like it has an air leak and run on problems.