1989 175 hp rough cylinder wall

[kmbvhlowe]

Have an 89 175 HP--number one cylinder reading 30 lbs, rest over 90. I changed the head gasket and while in there I found a rough spot on the wall of cylinder #1. I sandded it very lightly with som fine sandpaper. It looks like liquid ran into the cylinder and got hot scaring the surface. Cylinder still reading 30. What must I do to fix cylinder #1??

 

[emdsapmgr]

Re: 1989 175 hp rough cylinder wall

Sounds like you have a scuffed cylinder. That's where the alum from the piston skirt transfers to the cylinder wall. The ringset is no longer sealing in that cyl. You probably need to replace the rings and bore/hone that cyl. That's a complete teardown. I'd try to determine the failure mode before you do any work repairing it. Possible one of the rubber water diverters is out of place, causing that one cyl to run hot. Perhaps that cyl is running lean-check the carb jets that feed that cylinder for debris or other blockage.

 

[keefallan]

Re: 1989 175 hp rough cylinder wall

I agree with emdsapmgr. You need to tear it down. What did the head gasket look like when you opened it up? You need to find the cause or it will do it again. Blown head gasket? Water diverter?...............Good luck.