Help in selecting parts

[lp142]

My compression is low, right now is 120,90,90,70. I have tried decarbon a couple of times, and since boating season is coming to an endI figured I'd go ahead and replace the rings, the problem I'm having is figuring out what all do I need to order, I know I need a head gasket set, but when I looked on BRP for rings they listed std, .020, .030, I have no clue which to get, I'm assuming all I need is the 2 std. rings per cylinder and the head gasket set. My enging is 140HP 1979 Johnson, 140TL79R. Can anyone help me out.

Thanks

 

[rockyrude]

Re: Help in selecting parts

You won't know which rings to get until you open up the cylinders and find out how much wear is on them. If you have the cylinders resized for straightness or roundness, your machinist will tell you how far oversize he had to go and you get the new rings to match.