2011 CRF 250R needs more power! HELP!

I race C class and my stock 250f is down on power and I knowingly need more. It just has a full pro circuit T4r exhaust. Other than that, it's all stock. The exhaust added power but not enough to my satisfaction. I've won 2 races and got second in 2 as well in beginner class. So moving up to novices was hard with little power. So my question is, what are some effective mods that will give me considerably noticeable power gains? I'm considering porting and polishing the head, a 270 big bore kit, air4orce intake, etc.

Please leave me some advice on what I may be able to do to increase power. I don't want to buy a 250 2-stroke but I may have to if I can't get more power out of this 250f. Thanks1


hotcam stage 2 if you like to rev it out

air4orce airbox with backfire screen removed

carry momentum


should be more than enough



The issue with this testing is the fuel and the mapping, you can't just put a high compression piston in FI engine and hope get good number. You must at least change the Ignition mapping and if you really want to let it give all he can, higher octane fuel





Tell us how much you want to put in your engine before and don't be fool, this won't make you faster unless your skill is really in a high level

Edited by DarkCRF

Get your suspension re valved to your weight and riding

Get the ultimate solution, a 250 two stroke :thumbsup:


In all seriousness, power doesn't necessarily equal win. Forget the bullshit that MXA and every other magazine pawns off: Horsepower is king. That is just a flat out lie, end of story. If horsepower was king, 250 two strokes would be wasting the 250Fs in Aussie Pro lites. Instead Kale Makeham nailed second place overall on a 250sx this year. the two strokes didn't holeshot every race and the best rider won.


As a C class rider, I have serious doubts you are using all 37 horsepower hte CRF has to offer. Keep it in the mid range, don't just shift at the limiter because the curve falls flat on its face. Don't just lug it either, milk each gear for every pony its got. Thats the nature of lites class bikes. If you still feel it needs more power after you've sampeld hte mid range (I did, alot), or if you want the power lower, which you shouldn't ever have to do for a lites bike, by all means drop dollars on chamshafts and porting work. But if you want to really improve your speed, get your suspension done for YOU, beef up the front brake and burn the disc guard. Technique wins races, especially at your level, not horsepower.

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