04 800 Compression

I chequed my 04 800 renegade compression an one was 120 the other 110 is this good bad what is the stock compression ?[/b]

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anything more then 5 psi difference is a bad thing. Testers are inconclusive for proper PSI unless it is a good one, but when they say 10 psi difference it is normally not a good thing

Seems to me when the son had his 04 MXZX 800HO compression was 145-150psi.
Make sure you double check your readings with another compression tester before jumping to conclusions.

I chequed my 04 800 renegade compression an one was 120 the other 110 is this good bad what is the stock compression ?[/b]

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depends did you give equal pulls to each cylinder, that could be the differance of 1 missed pull,Compression test is alright ,if its running fine I wouldent give it a second thought,if you wanna check your top end do a Leak down test, much more accurate then a compression test,almost any local auto parts store can get you a leak down tester theres around 60 bucks

i agree with cory. its gonna be the off season soon, if a second gauge yeilds similar results i absoulutly would tear it down though.

i agree with cory. its gonna be the off season soon, if a second gauge yeilds similar results i absoulutly would tear it down though.[/b]

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If your readings are accurate it's a warning, absolutely take it down before a piston takes out the jug or worse a crank.

your rings are likely toast, but the best way to do it is take a reading on a cold engine, then run it wfo until motor is fully warmed up, then take another reading, compression should not drop more than 10 lbs at the very most.

i'd defnately check and recheck a few times with a few different testers. don't wanna cause yourself more work and money than needed

a friends rev 800 is 140lbs.do 1 cylinder at a time and pull till it dont climb anymore.hth

5 pulls each cylinder with the throttle wide open and the DESS key in your pocket should yeild 145-150psi. You need 2 guages to verify compression or one that you know forsure is right. If you are down that low, the rings are gone and maybe a few scratches in the nikasil too. This is common for the series III 800's.