rebuilt compression check on 951

[951racer]

what should a 951cc xp limited bored .50 have for compression because i rebuilt my ski and i know that i did every thing right cause the machine shop bored it for me but both cylinders have 120 psi on the dot

[Bill O'Neal1]

Re: rebuilt compression check on 951

Do not assume your guage is accurate unless you put it on another good 951 and it does not read at least 130 psi.

I usually get at least 135 psi after a 951 overbore at sea level.

When my good guages start to malfunction ( shrader valve failure ) they will pump up to the exact same pressure, usually about 120 psi, then quit climbing up in psi. Changing the schrader valve, they will go on up to the normal psi. Rarely if ever will an accurate guage read exactly the same for both clyinder, because rarely if ever are two clyinders exactly the same. There is always a difference between the clyinders, if only a pound or two. When a guage tells me that both are exactly the same, that is when I question the guage and change the valve.
My guage kit costs $230.00 and is very accurate, until the schrader valve starts leaking. That is why I keep extra schrader valves in my compression tester box.

[1fastski.com]

Re: rebuilt compression check on 951

what base gasket was used ? i have setup a few 951s with 120 PSI and they they have run great for 4 yrs now and i know and service the skis they get the life beat out of them and they have held up great . compression numbers as long as there even dont mean to much { unless there 50 psi each lol } but 120 is ok if you have 120 120 , now if you had 120 and 150 there would be a problem .

[951racer]

Re: rebuilt compression check on 951

yea i should try to invest in a new compression tester mine is a little old but would it make any difference because i did a compression test before i even started the ski after i put the new pistons in i did a test would that make a difference?

[Bill O'Neal1]

Re: rebuilt compression check on 951

How would I know if it made a difference? You did not say what the tests showed. Or am I misunderstanding your question?