When to rebuild?

[00Banshee]

At what PSI of compression should I start to worry about replacing the rings on a piped but otherwise stock 00' 400 EX?

[stocktires]

Well, Im kinda guessing here, but On R's is good to rebuild, or atleast re-ring when its 10-15 psi lower than what it is new

[00Banshee]

Thanks so much for your reply.

[timewass]

The Clymer service manual says that it should be between 100 - 128 PSI. So I would say if you go below 100 then time to open er up.

[Castor-426ex]

yeah generally youll be able to feel the power loss...most of the time...while youre in it might as well put a higher compression piston in it...lol:D