CRF's Only Forums

Hey , I have a 04 250 with very low hours. I'm original owner.

Id like to put in a hi-comp piston. I know the 04 head can't take too much compression. whats a safe ratio to run and still get a power increase ?

also what later year production 250 head will retro fit my 04 that would alow me to go with higher compression and handle the increased compression and power . thanks for the knowledge.

Oh I've done pipe and cam, etc. Ima horse power junky.

the '07, 08, 09 250R head will all fit your '04 and offer better port performance. the '05 and '06 will also but these do not improve the port performance. most go with the '07.

je piston 13.5

http://www.crfsonly.com/catalog/product ... ts_id/1154

ken

thanks ken for the quick response.

I'll take it that the 13:5:1 will work with the 04 head if I chose that route.

lastly the 07 head is different from the 04, but do they share any of the same parts ie. valves, springs etc.

yes it will work in the '04 head. the '07 and '04 head do share valve parts. however, it would be a bad idea to move over used valve parts into a new head.