Hi everyone it is possible I may have to rebuild my old johnson. I need to know where I can find oversize pistons. I also may need a gasket set for the power head. thanks in advance.
head gasket is easy, but oversize pistons might be a chore. search doug penn, you might find oe parts, maybe a light honing and fresh rings will bring it back to life.
The reason I may need the oversize pistons is I overheated the enginne at wot. There appears to be light scoring at the top of the cylinder. I will post pics as soon as I can.
You may also try calling Fairwinds Marina in Annapolis, MD They sell many NOS stock parts. They might have what you are looking for. They rebuild many of the old OMC motors. If memory serves me correct...my father rebuilt on old 1960 Johnson 40hp with a similar problem. He had the cylinder walls bored out and installed oversized rings...not sure if that is still possible but if it is....the folks at Fairwinds will know for sure.
Dan Gano at ganotech.com is another guy that has loads of OEM stuff and loads of experience. He's also about as reasonable to deal with as anybody I've done business with in the past.
Not usually. Most of the old powerheads I get still have good compression. It's usually the lower unit where the problems are in the older engines... Or the ignition system.
