Help tuning a 1991 KX 250

[djs556]

First let me say hello all. I am glad I have found these fourms. This looks like the place to ask the kind of questions I have.

I have a 1991 KX 250.
New piston
New reeds
New air filter
I just cleaned the carb
FMF pipe and silencer

When I first start the bike it reves up, then down, up then down. When I am riding, after warm up it does the same thing. When I pull the clutch to shift, it reves up. About the only thing I know to do when riding is to not pull the clutch too down shift? WTF??

Any help would be greatly appreciated.

[psyklone393]

i'd do a couple of things, first check for air leaks on your intake side. that's what it really sounds like to me ... but go ahead and be sure that your throttle cable is nice and lubed while you're at it.

oh ... and welcome to allthingsmoto! don't be a stranger.

-Z

[zuki]

Hey-welcome to the forums! And are you sure that you put your carb back together right?Also like psyklone said, it might also be an air leak. If you had installed the delta reeds,the gasket that comes with it sucks. That might be your problem right there.

[quadfather03]

what is your carberator jetting I am expericncing the same thing with my lt250 r quadracer and it is due to the fact that noone who had it last would change the main jet and piolet jet I ordered a new set you cant expect to get enough feul if your jets are for stock and you are running over. I will let you know how it work when I get the jets in the morning and tune the carb again.