Rmx 250 main jet question

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8/19/2017 11:26 AM

Finishing a rmx250 build with rm250 bottom end. Been chasing around a problem with it flattening out and not hitting power band. Idles good and peppy down low, but anything past half throttle it just wouldn't rev up. Here's the mod list...

1989 rmx250 top end and power valve
1992 rm250 bottom end
Epoxied crankcase chamber mod
Pro circuit platinum exhaust and silencer
Vforce3 reed assembly
Stock mikuni carb that came on rmx250

I got it dialed in for the most part to hit the power band but it won't go WOT without flattening out and bogging. I adjusted the a/f screw out and as I was doing so it would get better and better. Now it's screwed out to the point it doesn't seem to be making a difference. I didn't record what the jet size was when I cleaned the carb, but I know a stock one is a 230 and most newer models have a 260. Seems like a main jet issue... But hoping someone may have some more knowledge or has had some experience with an RMX/RM.

Thanks all