Need help picking crf engine

[quadfmx]

I've heard thev02 s r great but they got sev years on them now, I also heard 04-05-06-08 are good but the 8 will be high
I've read the 4 or 6 is bestfor a quad
Can anyone lend me some advice

[atvmxer79]

03 is the best hands down but they r old now so u need to find one in good shape in a dirtbike, look for the signs (adult owned, low hours, stock no mods, pics that look new, ect.) when u find one like that its your best bet. test ride it, shift it, look it over good, if it looks good without much wear and tear, cranks first or second kick, sounds good and smooth, and you can tell its been well taken care of. You cant tell all of this from just a motor, and if its in a quad its gonna be more beat up. just my two cents.