88 johnson 115

I took my johnson in for a tune up before a week long trip at the river and the mechanic said I lost a cylinder that three of my cylinders had 135 psi warm and one was at 35-40 psi. He quoted me at 1900 bucks to completely rebuild. I left the boat in the garage for 6-8 months. Then I decided I'd check the compression. All four cylinders where exactly 95 psi cold. The piston that I supposedly dropped does have what it looks to be water corosion around the plug, and very minor pitting on the cylinder head. Any ideas if I should just run it the way it is? Or trouble shoot the pitting and the corosion? If so how should I trouble shoot?

Re: 88 johnson 115

Id troubleshoot as if its getting water into the cylinder it could easily start overheating. Id pull the head and look at the gasket and look for where water is coming in and for any scoring on the cylinder walls indicating ring damage or bearings etc...

Re: 88 johnson 115

I'm puzzled as you did not tell us what, if anything, you had the mechanic do????????? If he did nothing and you got 95 psi on all four start by finding a new mechanic. Could be as simple as a head gasket.

Re: 88 johnson 115

Deff. need to find i new mechanic but money is a bit tight. So ill take the head off and check the gasket and hope that i see where water is coming in. If the cylinder walls, rings and piston seem fine will the pitting on top of the cylinder hurt the performance?

Re: 88 johnson 115

Unlikely the original compression was 135 on 3 cyls. That's a common compression number on the late 70's 135 engines-not the 1988 ones with the low compression heads. Likely the 95 lbs is a very normal/typical reading. Unlikely needing a rebuild as a result of those numbers only. The water intrustion can be a problem. Possible it's just a faulty head gasket, a relatively easy fix. If that's not it, then the exhaust covers probably need to be replaced and retorqued. These are not expensive fixes, but really need investigation before you decide to run it at all. You really don't want to hydrolock the engine... Pull the head off (with the water leak) and go from there. Once you've got the head off, post a pic of the pitting on the piston. Hopefully it's not a cracked ring.

Re: 88 johnson 115

Sounds good I will get a pic this week and post it up probly tomorrow or Thursday.