any 250ex'er out there with mx tires on?? i want to get some but was afraid i would lose too much speed, if its only like 3-4 mph then i'll go ahead and get them...help please

 

That was the same thing i was wondering. I would like to get holeshot MXR4's (19x11-9)

 

That's the only real sore spot with a shaft drive, you are limited to the tire sizes, as your gear ratio is set from the factory, and tire sizes will change that. My son's 300ex needed a gear change as soon as I put 20" Fast Trekkers on it, hit the rev limit so quick, it actually lost power, had to constantly shift to keep it from sputtering. The Honda rev limit is very low, you might want to check into an aftermarket cdi with a higher rev limit, otherwise you are looking at a lot of shifting to keep it in the right rpm range. I used to own a Recon, same engine as the 250ex, after modding the air box intake and rejetting, it was way peppier, but hit the rev limit a lot faster, and needed to be upshifted more to keep from hitting the limit. To answer your question, yes you will lose some top end, maybe 5mph, but don't go below 20" rear tire, the gear change will play havoc with your rev limit, unless the 250ex was given a better one than the Recon.