question on leaning out a cr125

[yong_ly07]

i have a cr125, i don't know what kind of jets are in, but its basicly running rich and the plug gets fouled easily after a day of riding, i am running a br9eix plug also, is it possible for me to not mess with the jetting and just try to adjust my air flow to the flow of fuel?, for instance running a universal k&n filter alone without the stock box, or stepping down to a hotter plug? plus i already have a pro circuit exhaust system that'll do...please help, thanks alot

 

[BJAWES]

I think jetting is pretty important, more importantly is to know what jets you have? I think you should fine tune the jetting to what you've added or changed not vise-versa.

 

[Suz-Loki]

I dont know if this is right, but it has worked so far. I tend to stay out of the top of the power band and bog the bike from time to time. One (part-time racer) friend indicated that I could change the mix from 32:1 to 40:1 (factory specs say 32). I haven't seen any wear, BUT I haven't fouled a plug since. I would not go beyond 40:1 though.

 

[Kevin003]

You really should jet your bike. Its not that hard just undo the screws or w/e it is on the bottom of your carb bowl and look for the long skinny gold jet. Use a socket to get it out and read the number on the side.

Then go to your dealer or whoever and go 2 sizes down and see if that helps. If your feel your bike pinging after that go up one size. You need to learn to jet according to the tempurature and elevation you are at. Sorry if im not making much sense, this jetting guide will make it much clearer.

http://justkdx.dirtrider.net/carbtuning.html