1977 9.8hp compression question

[clayton-2020]

I checked the compression on my motor both cylinders were 60psi I put a little oil because it has been sitting up a while, I pulled it a couple times let it set and came back later and checked it and it almost doubled 110-115psi could this be just because the rings are in poor shape and powerhead ok? I was just curious if I could just change the rings and get away from messing with the powerhead.How low can compression be for the engine to still function properly any advice appreciated

 

[hondon]

Re: 1977 9.8hp compression question

First of all,get a second opinion with a different compression guage on those dismal numbers.There is no head to pull on this engine but there are inspection covers that you can remove that will give you a little better idea what you are up against.

 

[Chinewalker]

Re: 1977 9.8hp compression question

Hi Clayton,<br /> I would try running it, then see what compression is. Dry cylinder can give you a low reading, but heavily oiled cylinders can give you a too-high reading. That motor will run quite nicely on as little as 85psi or so, so it's quite possible you're not too far off. Best news is that your cylinders appear to be fairly even. Compression checking is an imperfect science, as you may be discovering...<br />- Scott