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250f-cylinder compression ???

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Hoping you you guys could help me out...I just bought an '03 YZ250F, and was looking for some numbers on what would be acceptable compresssion psi on the cylinder. I wanted to test the compression and see if was close to specs., before tearing it open and dropping a piston/rings in.

Anyone know what the cylinder psi should be?

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I wanted to test the compression ...

how do you plan on defeating the auto-compression release?

jim aka the wrooster

'01 wr250f

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Ummm- I guess I didn't really think that far ahead, can you tell I'm a recent Thumper crossover.

Do you know of any way to get approx. readings on whether or not the top end needs rebuilt? Is it just a replace by approximate hours type of thing, sorry, just not really sure.

Any info would be great..

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http://www.thumpertalk.com/forum/showflat.php?Cat=0&Board=UBB10&Number=1294932

http://www.thumpertalk.com/forum/showflat.php?Cat=0&Board=UBB10&Number=1325539

but, a simple compression test will not tell you that it's the valve seats or the rings. if you are tearing down, first take the head off and use some very thin solvent to test the valves and seats for leakage. then continue downward to the piston and rings.

the guy you should talk to is steve (TTer Sunruh). he treats his engine like a porno mag -- he just can't keep from looking inside it.

see

http://unruhly.net/sunruh/hare/topend/index.html

and

http://unruhly.net/sunruh/hare/263/index.html

jim aka the wrooster

'01 wr250f

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