motocross engine mods

[rc41]

hey i am thinking of getting some engine work done i.e porting, valve job or high compression piston for motocross racing,
and was just wondering what engine work anyone who races mx has had done? and what they think of it in terms of the benefits of the extra power and does it have an effect on the engines reliability???
any help on this would be greatly appreciated

[csr250r]

If you dont have them already get pipe and filter with the airbox lid off.

Remeber with a high compression piston you have to run race gas, or in some cases 50% race gas pump gas mix. Race gas is anywhere from 5.70 to 12 bucks a gallon depending on how much you buy and what brand. Alot of people run CP and JE pistons in yfzs.

[rc41]

yea forgot to say i have a full CT pipe and K&N on already.
i'm using 97 octane at the moment, would that be enough??

[JR3]

im at 13.5 comp piston, hinson hub basket pressure plate 9 plate clutch kit and cover, cams and ported polished head. kand n pro flow kit and a TC exhaust. thing effin rips botoom end monster. I run VP C12 fuel

[#17YFZRACER]

ive got a port/polish job, weisco 14:1 piston, stock cams with cam mod, full system TC shorty pipe, and a fuel customs intake. i run VP U4.2. i get it for 8 bucks through a sponsorship. they knock off 8 bucks for me. this thing RUNS. its more of a mid to top end power but thats what you need on MX. it works well