Compression Troubleshooting

[PHeller]

After discovering my right side cylinder compression is a wimpy 60 psi, I went about trying to figure out why.

1) Bad rings. Oil in the cylinder increases compression (in my case up to 150psi)
2) Valve Clearance too tight. Valves not closing completely
3) Carbon buildup keeping valves from closing completely.
4) Timing off

Now I haven't had a chance to check my valve clearances, nor spray down the valves with penetrating oil.

Is there any sure way of checking to make sure the lack of compression is not valve related?

 

[mouser]

if your compression jumps to 150 with oil it is your rings. The low compression wouldn't change if it was your valves.

 

[PHeller]

What are the chances the rings are just stuck and not sealing correctly? Could a bath of ATF/Acetone loosen them up enough to create compression?

Or have the rings just more or less "let go"?

 

[Travis]

I'll wait for the experts to confirm, but my understanding is that if it hasn't been sitting, and you've been riding it, then they are bad and not just stuck. If it's been sitting and not running, the rings could be stuck and might free up with chemicals or running it longer. But like I said, wait for the experts to confirm.

 

[PHeller]

I've got a spare engine, so it wouldn't be hard for me to swap the two. The spare makes 155psi and it hasn't be ran in years. Guess I should be cycling it in prepartion...

 

[PHeller]

Tested it again tonight, after running it (to burn off any oil from the weekend test) and after adjust the exhaust valve I can get 150psi.

So...why is my right cylinder unable to run on its own? The search continues.

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