120psi Compression, but still runs

[SigEp368]

So I lost all power in the middle of the lake on my 1995 GTX (657), and had to get towed back in. I noticed the plugs were wet, so I took off the breather and saw fuel/ air blowing out the PTO carb.

I figured I had a RV issue or possibly a blown cylinder, so I ran a compression test with a 120/ 120 psi result. Turns out the issue was screw securing the needle valve pivot bar came loose, and I had a air leak on the pump side.

The ski runs fine now, but I am worried about the compression readings. From what I could find in here, it should be up in the 140-150s; doors this mean the engine is on its way out?

How far do I need to go in to fix this (e.g. new pistons rings and cylinder resurfacing)?

Thanks

 

[Coastiejoe]

150 is near perfect. 140 is very good. 130 is fine. 120 is the normal low where it can run ok but you will need to do some work in the winter.

 

[Coastiejoe]

How many hours are on the crank?

 

[SigEp368]

Not sure how many hours on the unit. I am 3rd owner, and was told that none of the owners lived on the lake. I am near St. Louis, so it was definitely only used seasonally, and in fresh water.

Thank you for the responses. Since the compression is off, do I need to run with a lower pop off?

Not looking forward to rebuilding it, but I am not the type to sell it to some sucker.

 

[Coastiejoe]

Top end rebuilds are easy and cheap. The issue is, if there is say 300 hours on the crank and you rebuild the top end, the crank end will likely fail shortly there after. So if there is 300 or so on it, you want to seriously consider a complete rebuild or purchase a remaned engine.

 

[SigEp368]

Thanks for the info. This may be a stupid question, but if I rebuild the top now, will I have to rebuild it again if I have to go in to the crank later, or will I be able to save time and money by focusing on the lower rebuild at that time?