2010 Polaris Dragon 800 Compression

[peakperf2]

What should the compression be on a stock 800? Mine is only 118 each side. Time to clean power valves or re-ring? Has 3900 miles and I live in Wisconsin.

Scott

 

[peakperf2]

I just bought this sled but my buddy told me these have decompression holes which probably why the low numbers.

 

[Vanman]

That sounds pretty low to me. I would guess should be 130-140 ish. Better talk to a dealer for find out for sure.

 

[Kraven]

What should the compression be on a stock 800? Mine is only 118 each side. Time to clean power valves or re-ring? Has 3900 miles and I live in Wisconsin.

Scott

118 psi is acceptable as gauges vary

I'm actually surprised a 2010 D-8 survived for 3900 miles

If you're going to rebuild it, I'd highly recommend one of the "piston & cylinder spacer and/or long rod kits" offered by INDY DAN, MTNTK Performance and others

Have the cylinders miked, and re-nicasil'd if need be as they're notorious for being out of spec

 

[jeepin270]

If it has that many miles with stock topend, it would probably be in your best interest to freshen it up. It could be a lot more costly a month into your riding season.

 

[SU27]

What should the compression be on a stock 800? Mine is only 118 each side. Time to clean power valves or re-ring? Has 3900 miles and I live in Wisconsin.

Scott

These D8 are generally low compression engines. 125 is very good after break-in procedure. Again, your altitude plays role too - higher altitude makes compression lower. So, Wisconsin elevation+3900 miles+stock D8 = 118. sounds about right.