dirtbikr99

Member
Nov 21, 2002
180
0
I have a 1999 cr250. I just had motor work done and now my compression just seems way to high. I am going to do a compression test on it soon to find out. The cylinder was ported cases matched, new reeds, oem piston and rings. I wanted to raise the compression a little so I had ten thousands taking off the head. Is ten thousands a reasonable amount to take off?
what is stock compression?
what would be to high?
 

motometal

LIFETIME SPONSOR
Sep 3, 2001
2,682
3
why do you say it seems too high?

If it hasn't been done already, you should measure squish clearance. If it's too tight you could crash the engine. The builder should have either measured this or instructed you how to. You need some .060" solder and a micrometer or good calipers. Bottom line is it's probably usable but to be safe you should run race gas.
 

darringer

LIFETIME SPONSOR
Dec 2, 2001
1,029
0
When I had my '99, it would pull 210-220psi, stock cylinder with Wiseco piston, and with a fresh top end. This was taken on a cold engine, at sea level.
 
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