2006 Suzuki df140, very low hours but issue with compression

[cabound]

I am looking at purchasing a 2006 bay boat with a 2006 df140 motor with 60 hours. It is a 1 owner boat, by an older gentleman. I had the boat taken to a boat shop for a prepurchase inspection, and they told me it had low compression in the #1 cylinder and bad leak down in two cylinders. The compression was 155 in #1 and in the 170's in the other three. It also was not pumping any water, so they couldn't run it for very long, but they said it was long enough to warm up. They told me they would have to get into the engine to any further diagnosis. I know the boat has sat for a long period, and sat for long periods between each use. I also had them pull the exhaust plug, and there was not any corrosion on it. My question is this, could this be something as simple as carbon buildup from poor plugs and sitting so long, causing the low and inconsistent compression? Any advice would be greatly appreciated, thanks!

[Hoosmatroos]

A leak test could indicate if it are the valves or the piston. But clearly there is an issue. Hard to tell what it is at this moment.

[Moonlighter]

Valve clearances could be out - need to check? They are supposed to be done after 200hrs anyway.

[jHydroman]

Since the engine only has 60 hours on it and long periods of nonuse I doubt that the valves are out of adjustment. Guess it's possible that a valve stem could have bent if it was stuck. I remove the spark plugs and place some oil in each cylinder and turn the engine a few times and then repeat the compression test to see it make a difference.
This is just another example where low engine hours is not necessarily good, The fact that the engine sat for long periods without running that the oil film on all moving parts was nonexistent.

Jim

[artdf175]

my advice is don’t buy a problem!
the downside if things won’t straighten out and the engine would need a major overhaul you might need to spend some big bucks.

however having said that - find if the break-in instructions were followed to the “T”.
Then check the valves- they can be out of spec and not a terribly invasive process.
If the breakin was not done correctly the rings may not have seated correctly.
The water problem is more than likely a bad impeller. regardless of hours the blades get compressed out of shape and then won’t pump.
Art