Compression:What can effect it

[AdamXP800]

I'm helping a friend do some maintenance on his 95 XP. When taking a compression read it's coming up way low. I have tried it on all 3 of my gauges. It's dead even on both cylinders but low. The machine runs great though. I noticed his starter does not sound right and sounds weak. I know the battery is fine, we pulled my brand new one out and even tried it. My question is: Can a weak or flaky starter cause a lower compression reading?



95 XP800!!!
Keep the 2 strokes alive!

 

[Coastiejoe]

Yes. If it does not rotate at max starter RPM, the compression reading will be lower.


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[AdamXP800]

Thanks Coastie, that's what I thought but just wanted to be sure.



95 XP800!!!
Keep the 2 strokes alive!

 

[SabrToothSqrl]

I believe people put too much emphasis on the compression numbers. As long as it reaches appropriate max RPM in the water, and runs fine, run it.

The only exception being if one cylinder shows 100 PSI, and the other shows 50. That's a rebuild.

 

[AdamXP800]

I do tend to agree Sabr but I do like seeing that 150 on both cylinders at the end and beginning of the season lol



95 XP800!!!
Keep the 2 strokes alive!

 

[andrewterri]

I had the same problem and mine was due to a bad ground connection. You might try pulling the ground cable as it is only one bolt then try to clean it. Mine was so bad I had to use a grinder to clean the cable ends then wire brush the heck out of the mounting point. Once I did this on mine the starter was turning much faster. Just a thought...

 

[AdamXP800]

We have run all new grounds and wires on this machine. I think his starter is weak. You can hear it struggling and the bindex does not function correctly on every start



95 XP800!!!
Keep the 2 strokes alive!