Johnson 125hp bad cylinder

[rocks beware]

I bought a 1971 Johnson 125hp over the winter and just got word from my mechanic that one cylinder has low compression. He said it's not scored and thinks the piston may be frozen up a bit. It appears that there is a little sand or debris in the cylinder case. He is gonna spray some stuff in try to run it to loosen it up. Does this sound like a reasonable diagnosis or should I just cut my losses. It also has an erratic spark. Thanks for any opinions. <br /> Rocks<br /><br /> ".......... work is for people who don't know how to fish."

 

[OBJ]

Re: Johnson 125hp bad cylinder

Hi rocks....<br /><br />Sounds like what the mech is going to do is spray some decarb in the engine and try and losen up the rings. Did he say how much lower the compression on the cylinder was as compared to the others? If the compression wasn't to much lower, then the decarb is a resonible thing to try. If it works, make decarbing a yearly thing and run a product like carbon guard from Bombardier or I believe it's called Sea Foam. Iboats has this in their store.<br /><br />The erratic spark can be caused by several different things. If you are not familiar with the engine, let the mech check it out for you.<br /><br />Good Luck!