97 CR250 idling problem

[dcouch]

This is my first time posting on this site, but I have used a lot of your advice recently when I rebuilt my 97 CR250.

This is my first true MX bike. These things are rockets! I've owned 4-stroke trail bikes and even a KDX 250, but they can't hold a candle to this thing.

I bought this bike a couple of months ago pretty cheap, but it needed the topend refreshed. So while I was at it, I tore the bottom end down and replaced the crack, crank bearings, all seals and gaskets, along with new proX piston, rings and wrist pin. I checked the carb completly out to include needle clip position, float level, wear on the jets, etc. All jets are factory standard and the power jet solinoid works. The reeds are in good shape, they look like dual stage reeds with no reed stop. It has a FMF fatty pipe with a good bit of damage in it right where the pipe makes the U shape just past the frame. I plan on replacing it with the same pipe as soon as i can save up the $180.00. The pipe is not restricted, just deformed a good bit.

With all that said, here is my problem. The bike cranks up easy, and runs great thru all the gears, plenty of power, but in an idle it sounds like this: rrrm...rrrm....rrrm....rrrm. I've played with the idle adjuster and air screw in all postions. You can get it to idle steady for a little while, but then goes back to the rrrm....rrrm.... I've been told that these bikes don't like to idle very well. Is this the case or is there something else I can check or tweak?

Thanks,

Danny

[darringer]

If it's surging at idle it would probably be too lean on the pilot circuit. It can and will idle very well with some jetting changes.

[dcouch]

Thanks, I will definitely check into that.

[offroad101]

more than likely it is that Carb. I have done everything imagineable to make mine right, but still does what yours does. The only way I think I am gonna take care of mine...which doesnt bother me, is to swap the carb for a better model.

Out of curiosity, if you want to keep your pipe....try this
[Only registered and activated users can see links. ]

they removed some dents from my pipe, can't tell where they were now

Back to your carb issue, did you adjust your floats?

[dcouch]

Thanks, that was what I was affraid of. The bike runs great. It was just aggravating not being able to get it to idle right.

I checked the float level and it was right on with what the book said, which I believe was 16mm.

I want worry with it anymore, I only ride it for fun anyhow. I usually don't give it much of a chance to idle anyhow.

Thanks,