03 Cr250 Bottom End

tommyaus

Member
Feb 22, 2010
11
0
hey, ive just recently got back into riding and bought a 03 cr250.
after a few rides it started to leak oil through the pipe thanks to the bottom end seal gone and a wobbley crank.
im gonna get the bottom end rebuilt and was wondering what sort of upgardes could i do to give it more poke down bottom, and if so would i have to do some piston work. the top has recently been rebuilt but havent had a look at it yet. i was gonna attempt to do the bottom end myself but i dont have the space.
also what are some other good mod's to do, its got fmf fatty, powercore 2 pipe but got a shorty on the way. was thinking of boyseen reed kit too, are they worth it?
any ideas would be great.
thanks
 

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
Rebuilt properly, and jetted with the correct oil ratio, you will find all the bottom end you need. Or something is not rebuilt correct. Off bottom, I would get the boyseen rad valve. The only other way is an overbore for more power everywhere. Vintage Bob
 

tommyaus

Member
Feb 22, 2010
11
0

no worries, i was looking into doing a reed kit. what are the best reeds to get?
 

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
Eric Gorr makes no mention about an issue with no bottom end. He does recommend the v force because its more reliable to the chip prone stock reeds. There you go. But he also adds that the bike has a real short power band, it needs a lot of machining to give it a broader power band, mid to top, but he can do it. If you plan on hopping it up, get the v force, if not get the boyseen. I always took the boyseen as bottom~mid, and the v force more mid~top. Vintage Bob
 
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