after exhausting enough bolt on mods, i've decided i want to go the motor mod route. everybody always complains about hondas having lousy bottom end on the 250's. i've noticed they also have the lowest compression ratio at 8.5:1. my idea is to simply have the head turned down to raise the compression similar to a yamaha's at 9.5 to 1, and have the ports polished but not altered. will i see a substantial difference in the bottom end power, or will it be miniscule? the tuners i've spoken to are all pushing for a port job as well. i understand they can get bigger gains with additional porting, but i'd sooner take it one step at a time, and so would my wallet.
this bike runs fine on pump gas, which i also like. theoretically, raising compression requires higher octane levels, so i'm logically thinking i MAY need race gas now. but but but-
i have many friends running the higher compression yz250's on pump gas without incident, so how is that? is the octane requirement also dependent on the characteristics of the porting?
this bike runs fine on pump gas, which i also like. theoretically, raising compression requires higher octane levels, so i'm logically thinking i MAY need race gas now. but but but-
i have many friends running the higher compression yz250's on pump gas without incident, so how is that? is the octane requirement also dependent on the characteristics of the porting?