What does this look like?

RussGW270

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So, waiting for the engine to cool, probably will not be able to test compression till tomorrow when it is cool enough. That being said, maybe just a sloppy install but I noticed what looks like gasket material and ....residue? Not sure if it is relevant or not.
I think I know why I have low psi on a single cylinder. A leak-by test would confirm but not wasting money on that when I can resolve this first.

check out the photos. One shows a clean install, the affected cylinder is right below what appears to be another horrible maintenance...looks like a bad gasket install.

ignore the small oil on the plug below, that was the mystery oil I added.

This could explain why the engine runs fine and the oil shows no sign of wear.

Trying to locate this area on the simyamaha diagrams

R
 

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RussGW270

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Never mind. If that anode were leaking there would be water in the oil and the oil looked fine.

R
 

wspitler

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Those anodes are immersed in the water jacket. One seems to be leaking a bit of water externally. No big deal. They have a rubber gasket that seals the water from leaking out, very easy to replace. not related to the oil at all.
 

Sparkdog118

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Rubber may have oozed out if motor was overheated. This is what is behind the cap. It will have a rubber doughnut around the neck of the zinc.
 

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RussGW270

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Nod. Gotta pull it and replace the grommet no matter what
 

wrxhoon

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So, waiting for the engine to cool, probably will not be able to test compression till tomorrow when it is cool enough.
Engine compression test should be done when engine is at operating temperature and WOT. A low compression on one or more cylinders could indicate bottom end ( warn/broken sticky rings, warn bore etc) or valves . If you have low comp on one cylinder and you squirt small amount of oil then check comp again, if comp doesn't change more than likely the problem is on the top end, if it increases problem is on bottom end.
A leak down test is more comprehensive test if comp test comes low.