Compression test on '14 Pro 800

HCR800<3

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Hey there ladies and gents. Did a compression test on my '14 pro 800 the other day. It was 110 at wide open.. Good or bad? Polaris dealer I called said they won't do anything within 10%.. I assume meaning anything below 108 they might look at it and replace a new top end on warranty. I'd rather that then getting towed out later in the season and needing a new crank and all after seizing .. Thoughts and opinions? :)
 

TylerG

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Hey there ladies and gents. Did a compression test on my '14 pro 800 the other day. It was 110 at wide open.. Good or bad? Polaris dealer I called said they won't do anything within 10%.. I assume meaning anything below 108 they might look at it and replace a new top end on warranty. I'd rather that then getting towed out later in the season and needing a new crank and all after seizing .. Thoughts and opinions? :)


my thoughts, you're too hard on chit Sam :)

I'm sure some of the poolaris guys will chime in soon!
 

floogan

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Test both cylinders ie mag - 110 psi then pto should be no lower then 99psi or vice versa
there is no actual compression specification
ie testers could be off 5 psi on tester to another
so if you had 120 and 108 there would be an issue
 

Staple_STI

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I did mine and it was 118 per side. I thought spec was around 120-122 for these Liberty Engines
 

Merc63

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Try another gauge. Those gauges are known to be off lots of the time.
 

JMCX

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I do a compression test after every trip. On my 13 Pro 800 I have never had it as high as 120. Between 107-115 is typical with my gauge at Calgary's altitude.

I wouldn't give five cents for some compression testers but most are good for cylinder to cylinder comparison.
 

dragonweld28

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Just do yourself a favor and put the MTNTK fix kit in and be done with it. I know lots of guys say," I still have warranty," but why would you risk a helicopter bill and losing a weekend riding when you can rebuild the top end for less than $700. They run better, have more power and are more reliable. Its a win, win, win. Polaris has the worst motor but, I think, but the best handling and riding characteristics. Screw that warranty and get the fix kit. Even there kit with a head is only $799. That's dyno'd for almost 8hp. I have been dealing with these ****ty motors for 5 years now.... just get the fix kit.... Rant over.
 

Wilk INStheWEST

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Just do yourself a favor and put the MTNTK fix kit in and be done with it. I know lots of guys say," I still have warranty," but why would you risk a helicopter bill and losing a weekend riding when you can rebuild the top end for less than $700. They run better, have more power and are more reliable. Its a win, win, win. Polaris has the worst motor but, I think, but the best handling and riding characteristics. Screw that warranty and get the fix kit. Even there kit with a head is only $799. That's dyno'd for almost 8hp. I have been dealing with these ****ty motors for 5 years now.... just get the fix kit.... Rant over.
Agreed, my 12 engine is currently torn apart and ready for the MTNTK drop in kit to be going in.
 

Jesse_01

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110 is about right for a cold compression test . The Polaris sleds have lower compression than the 800's. Main reason why the poo make less power. A piston fix kit will bump you up 10 psi or so.

When running a turbo its coming for them to wear out the rings and lose psi also. The piston will look fine but you will be down 15-20psi.
 
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