First Bike - GS650G - Rusty Crusty

[salty_monk]

Maybe the stem seal is deformed & holding it up? Just a thought. The wire around the seal might have rusted whilst it was sitting. You can change those without removing the head so might be worth a try. Bent valves aren't very common on these if there is nothing else amiss...

[Eric4]

Here are a few more pics. The more I borescope, the sadder I get. By the way the light is reflecting off the imperfections, it's really looking like a gouge along the ring circumference. The slight vertical scratching doesn't seem to have moved the dark ring, so in my eyes, it's not soot/carbon, but a gouge (see pic 1). There was some pitting looking imperfections lower into the stroke as well.

I do recall when pulling the plugs, that an outer cylinder didn't' have a tight plug installed. If some water got in after ~15 years under a tree, I could see how the rings might corrode away against the cylinder wall.

That still leaves the stuck valve issue too...

[salty_monk]

Yeah.. you’re not likely to find a lot of 650’s around to drop in another engine. Hope you get lucky!