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dober250R
06-18-2005, 03:46 PM
I just rebuilt my motor (new piston, rings, fresh bore, ported cylinder, and I had the head milled). I went thru 3 heat and cool cycles, then checked the compression. I could only get 180!! I know this is stock for a 250R, does the compression go up as I break it in?? thanks.

06-18-2005, 06:44 PM
You do a pressure test on it to see if its leaking anywhere?

dober250R
06-18-2005, 08:30 PM
how do you do a pressure test? I know how to do a compression test, i know these 2 aren't the same.........

06-18-2005, 08:38 PM
compression test tells you our PSI, Pressure test checks for leaks, either around the ring / gaskets etc.

What psi were you getting prior to redoing it?

dober250R
06-18-2005, 08:49 PM
I had a different head and cylinder on it. On that one with worn rings, i was gettin 210, head milled also, no porting on the cylinder.

dober250R
06-18-2005, 08:49 PM
how do you do a leak test?

06-18-2005, 09:01 PM
Well sounds to me your new head is a high dome.... which would give you lower compression ratio.

06-18-2005, 09:02 PM
Read this

http://www.off-road.com/atv/ptester.htm

dober250R
06-19-2005, 09:37 AM
yeah, the dome is about .100 taller than my old one. Thanks for the pressure testing instructions!!!

06-19-2005, 10:39 AM
Well there you got .1 is alot so you cant expect to see the numbers you had before.