I just picked up a low hour 02’CR250 and would like to get some input on baseline jetting specs. I just received my manuals from Helm and they offer detailed jetting specs to start with, but I’d like to know any other tips that may help to keep things crisp from idle or WOT. The bike will be used purely for fun (mostly trail & some mx) at an altitude range of 3,000 to 4,000 ft with outside temperatures from 70F to 100F. The bike currently has a Boyesen RAD valve & Pro Circuit 296 canister with everything else being stock. The fuel being used is 91 octane pump swill mixed @ 40:1 with Mobil MX2T.
I’ve read comments on various forums about filing the bottom of the slide by 2mm, which reportedly improved the low end throttle response & power by a noticeable amount. Has anyone here done this? What kind of results did you get?
What jetting specs did you find worked best on your similarly configured 02’CR250 and what altitudes & temps were those specs based on?
Has anyone here dialed in their Mikuni as best possible, then installed the Keihin 38mm PWK Air Stryker carburetor to compare its performance? Is there a definite improvement with the Keihin carburetor? What kind of improvement did you notice? Is this a direct bolt on or will I need a different boot to make it look sano?
At some point in time I’ll be adding some flywheel weight (~10oz) to smooth out the power delivery and will have the cylinder ported Mo-Better Everywhere, but for now I just want to dial it in as is and have some fun with it.
I’ve read comments on various forums about filing the bottom of the slide by 2mm, which reportedly improved the low end throttle response & power by a noticeable amount. Has anyone here done this? What kind of results did you get?
What jetting specs did you find worked best on your similarly configured 02’CR250 and what altitudes & temps were those specs based on?
Has anyone here dialed in their Mikuni as best possible, then installed the Keihin 38mm PWK Air Stryker carburetor to compare its performance? Is there a definite improvement with the Keihin carburetor? What kind of improvement did you notice? Is this a direct bolt on or will I need a different boot to make it look sano?
At some point in time I’ll be adding some flywheel weight (~10oz) to smooth out the power delivery and will have the cylinder ported Mo-Better Everywhere, but for now I just want to dial it in as is and have some fun with it.