Wet Compression Test 120 Rises To 170

[bobbyg]

2007 15HP Johnson 4-Stroke. Problem is, the motor did take a long walk off a short pier and was submerged at one time. Sat for a couple years and recently I cleaned it up. Cleaned out all the obvious surface damage (rotor, stator, new starter, new coil plugs etc). It idles like a kitten but when it gets to about half throttle it shakes and shimmies as if starving for gas. Carb was ultrasonicked 3x with no improvement. Dry compression test (with throttle wide open) is 120 Top 130 Bottom. After adding 1 tsp oil, 170 Top 190 Bottom. Not sure what cold specs should be but 120/130 seems a bit low to begin with. However, increase of 50/60 (wet) points toward rings. Perhaps frozen or rusty rings? Would shimmy be caused by lack of compression?

 

[faztbullet]

I would be worried what internal surface conditions are.