Bad Compression Tester or Bad Me?

[jteneyck]

Actually, I posted this before, but a recap of this saw:

I got it from a friend who works for the power company, after one of their crew blew it up.  They didn't think it was repairable at reasonable cost.  I thought the cylinder looked OK, so I cleaned it up and put in an aftermarket piston/ring.  I ran it rich for quite awhile and then set it like I set all my other saws.  It lasted three years and then died one day.  Looked through the exhaust port and, sure enough, another scored piston.  The cylinder still looked OK, so I put in another piston/ring, and replaced the impulse tube at the same time.  Putting it back together I stripped out one of the holes in the (cheap) plastic that the carb. attaches to.  I put some epoxy in it and threaded the screw into that hoping it would hold.  Guess not because that piston lasted one hour.  At that point I questioned everything, and even thought about just selling the saw for parts, but finally decided to make a project out of rebuilding it one more time.  When I took the saw apart the cylinder bolts were not very tight, so maybe I had an air leak there as well.  I bought a piston/cylinder from Bailey's, but before I put it in I did a pressure/vacuum test on the crankcase and it was OK.  The bearings in the bottom end all felt good.  I put the new cylinder and piston on, torquing the bolts several times and even used Locktite medium strength on the threads, and put a new top bearing in the crankshaft, although the old one looked OK.  I then changed the screws to bolts when I put the carb. back on, and installed another new impulse line.  The rubber boot between the carb. and cylinder looked good so I didn't replace it.  I cleaned out the muffler real well when I put that back on, but haven't opened it up because it's empty inside and pretty open already.  But that could be something to consider in an effort to get it run cooler. 

That's the saga.  Hope I got it right this time.  Haven't run it more than a few minutes yet and, trust me, it's set rich by sound and smoke.  If anyone has any comments, ideas, etc., I'd be pleased to hear them.  Thanks.

John