01 CR125 Runs rough at low speeds

[dirtbike_madness]

My CR bogs down and has trouble cleaning out at low speeds. When I try to clean it out before taking off, it seems to not really completely clean out. I pop it in second gear and it's woa poney, time to rock. Once it's cleaned out it rock n rolls like crazy. I would like it to clean out quicker so that I can have a better response in first gear.

Where do I start? Does it sound as if the main jet is too big? Air screw out too much? Oil to fuel ratio to oily?

Open to all ideas! Thanks!

Oh yes, one more thing. It HATES to idle, period. I'm so jealous when I'm next to my buddy, and his is just ideling away like nothing!

 

[marcusgunby]

you need to do a search on jetting for the cr125-we did lots of work on this and had some much better jetting specs for the 01.

 

[usgpru27]

Turn in the air screw 3/4 of a turn and see what happens. Sounds lean. I took mine out this weekend in the cold and it did the same thing. Turned the screw in to 1 1/4 out and it was great.

 

[BooBoo]

Have you fouled many spark plugs? It may also be too rich. If it's fine once it gets on the pipe, my guess would be the pilot jet is your culprit and is too rich. The power valve may also be sticking open if you don't have much power down low...

 

[dirtbike_madness]

It's like it's loading up when I'm just putting around in first gear. I can pull in the clutch, rev it out full throttle, and it really never cleans out. But... as soon as I get out of first gear and give it the gas, it pops into the power band. If I keep the rpm's really high, I can putt it around in 1st gear, but it's an animal at that point and very hard to control. I would love to have more bottom range. I can't say that it's fouled a plug. I'll see if I can pick up a smaller pilot jet and give that a try. Any other ideas, feel free! Thanks guys!

 

[NacNac250F]

Try leaning the pilot jet a size or two. If that does not work your powervalves may be stuck open.