question about ring size

[kfouryou]

Hi guys I have a 88 125 hp force queston on the size of rings to use.My compession is as follows #1 134 #2 50 #3 132 #4 131 .So the head gasket is new .I took off the head and checked the bores down near the exhaust ports #1 3.313 #2 3.321 #3 3.310 #4 3.320 .Can I get away with honing cyclinder #2 or do I need to bore it?.

 

[Frank Acampora]

Re: question about ring size

Stock bore is 3.3125. Stock specifications for wear, taper, out of round, or barrel shape is .005. Thus, a marine mechanic would recommend overboring cylinders #2 and #4.

However: If the bores are clean and not scored, these engines have a habit of breaking the top ring for no reason. Check #2 and if the top of the piston is deformed from the broken ring, replace the piston. If money is tight, you can try to get away with a simple honing and a standard piston. But, understand that cylinder #2 is already at .0085 over as is #4 at .0075. Thus a .010 or .020 overbore would be the best route to take.

 

[kfouryou]

Re: question about ring size

If I were to hone cyclinder 2 I could get away with .10 ring set?I was hoping to get another month or so . What sucks is this head was a replacement for a cracked head that had good compresion.