tomconnolly
Seaman
- Joined
- Jun 23, 2021
- Messages
- 55
So I pulled the power head and removed exhaust cover on my engine today to fix a water leak into bottom cylinder. On inspection I find the top piston is missing it's top ring entirely. That cylinder ran 100 psig on compression test and other 5 ran 120 last week before I started this project.
Is it even possible to replace only the top piston and rings since 120 isn't too bad compression for the other 5 cylinders? Or must I remove the entire crank and therefore should I just buy the other 5 sets of rings and replace them all?
And if I have to take off the entire crankshaft, should I go ahead and have the cylinders tested and honed if needed?
What I rl am tempted to do is put the exhaust cover back on and run it as is, with the missing ring. The cylinders and pistons, including top one with missing ring, all look fairly smooth with no significant scoring. There is some barely visible scoring on piston #5...
It doesn't appear that this engine has ever been opened by looking at the bolts all with paint on them. Other than these recent discoveries the powerhead and lower unit all seem to be in good shape.
Is it even possible to replace only the top piston and rings since 120 isn't too bad compression for the other 5 cylinders? Or must I remove the entire crank and therefore should I just buy the other 5 sets of rings and replace them all?
And if I have to take off the entire crankshaft, should I go ahead and have the cylinders tested and honed if needed?
What I rl am tempted to do is put the exhaust cover back on and run it as is, with the missing ring. The cylinders and pistons, including top one with missing ring, all look fairly smooth with no significant scoring. There is some barely visible scoring on piston #5...
It doesn't appear that this engine has ever been opened by looking at the bolts all with paint on them. Other than these recent discoveries the powerhead and lower unit all seem to be in good shape.