200 rm25 really fast idle..help

Ok a little background.. and the title should read 2000 rm250.. i had my RM250 at the dunes.. it ran great.. came home, fired it up when i got it out of the truck and rode it around the house and put it in the garage.. a couple days later i go out and put the knobby tire back on and take my "dune" jet out (a 172 i believe) and put my mountain jet in (a 152) anyway i go to start it and nothing, so i clean and oil the air filter, new plug and figure she will fire right up as usual... nothing.. i kick and kick and kick... nothing. check compresssion it is sitting right at 150, spark apears good. take the carb apart and clean it throughly check to make sure gas is getting to the carb.. all good.. put in another new plug.....nothing, repeat this procdure 2 more times.. nothing.. so i resort to pull starting, after couple mins of pulling it starts! idieling like the throttle is wide open.. the idle adjust screw does nothing, the fuel mix screw does nothing. spray all around to the carb and intake with wd 40 to see if it has an air leak.. nothing. kill it and kick start it a couple of more times.. starts on the second kick but still extreamly high idle.. the choke made a little difference but the choke adjustment did nothing.. i am soo stumped right now??? could i have done something to the main needl when i took the throttle cap off.i just have no clue what to do now.. ohh tried it with the 172 jet also no differnce

If there is no air leak and assuming that carb is working properly, all i could think of is a problem with throttle cable. Sometimes when I loosen the screws and move the carb towards myself to get the top cap off it tightens the trottle cable, but when I put it back I have to pull the cable back out from where it sits under the tank. It could be pinched somewhere. I would also ispect it for air leaks again thoroughly.

you nailed it!! the cable was split under the boot so when i turned the carb to change the jet it "stretched" the cable causing it to tighten the throttle.. it was basicly running at almost full throttle which explained the hard to start issue! pushed the cable back together and taped the heck out of it for a temp fix till i can get a new cable. works like a champ.. idles and starts on the second kick now

I'm glad that helped

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now