2002 CR250 idle issues.

[Vasklevox]

My engine is currently running excessively high at idle. Before winter set in I found my throttle cable was starting to go bad (sticky, lube isn't working, just worn.) I've since disassembled the bike to include bodywork, tank, subframe to make getting at the carb a bit easier. I've the cable to the point its' not too stiff but takes a second to come back down to idle, however; the idle will not drop from what I estimate to be 'about 1/4 turn of the right grip.

I backed off the cable adjuster at the throttle housing, lowered the idle itself at the carb and sprayed starting fluid around the intake to see if I was sucking air after the carb, all to no avail.

I know that RC valves need their cables tightened periodically, though, they seem to be within' adjustment I believe.

Bike was picked up second hand from who knows how many hands, only personally ran the bike 7-8 times in the past year, recently replaced the spark plug, ran well, then the idle.

Running from what I can tell to be stock internals on the carb, 40:1 Polaris sled oil (what I've had on hand, runs well *Shrugs.)

Any help would be awesome, thought it might have been from the one time I took'er up on the pavement, checked all hardware n' shes' tight as need be, still confused.

-Samuel

 

[kaboom1371]

my first guess would be replace the cable with a new one. if it's sticky it probably isn't letting the slide go down all the way.

 

[Vasklevox]

Oh but of course, have one on the way, however, sticky would make it take a while to go down, checked it with the airbox removed, gettin' full down motion, still idles high, just took it for a ride in town (gravel roads) and the cable hung up once... Other than that, its' manageable, but I still don't like it.

Hate livin' in the southeast section of Alaska, theres' nothing here, so parts have ta come from bum f--- somewhere else. Makes me wish one of my other machines had something comparable for a spare.

Thanks though, already checked, n' then double checked.

 

[Patman]

Is the throttle tube in good shape?
Grip rubbing on the end of the bars?
Throttle housing is spotless and free of all crud?
Carb slide is not damaged?
Carb needle is seating correctly?

 

[Vasklevox]

(Edit: Cable-) Housing is in good condition, little slow to return off of idle, but slide DOES return all the way down.

Grips do not seat all the way to the housing, grip tube clean and not rubbing on bar end.

Housing cleaned out and lubed with TW25B grease. (You'd have to see the stuff to understand.)

Carb slide is still polished to a mirror finish.

Slide and needle are seating all the way down.

I've just been riding it, the idle sometimes comes down to near stock conditions, sometimes not, checked multiple times not to ensure the slide is returning all the way down, idle screw backed off to where its' not even contacting the slide. Almost beginning to think maybe something is way up in one of the jets that I didn't see, would something in the air speed / mixture jet cause it to run high? I've mostly dealt with simpler Keihn four stroke carbs, took this one off the bike and theres' like 90 effin' hoses running everywhere. Know of any article that can give me a crash course on the two-stroke flat sider?

 

[Vasklevox]

Well, sorry for the double post... But eff off.

Nevermind the issues, though I still don't believe its' the throttle cable (I've held the slide down) I'm just going to wait until the new one comes in, if I still have issues, I'll be in contact with ya'll.

 

[spark250]

after you check everything mentioned earlier and change the cable, check for air leaks, like a torn carb boot or a crack in the pipe. I've had that happen before.

 

[Kawi4life]

Heh, all my 2-stroke MX bikes where always set for no idle.