got a few piston/cyl questions

[pinesfarm]

well i got a real nice straight gased 372 for 50 bucks along with a straight gased 036 for 40 and whats the do's and dont's with replacing the pistons and cylinders im going to go all oem on both of them. Since i have the saw apart i figured why not see if the crank is ok on them what should i be looking for if it happened to be malfunctioning?

one more the mufler on the 372 doesn't want to seem to budge off the cylinder am i missing a bolt or two?

if anyone could lead me in the right direction that would be great!

pics to follow tomorrow so far got the 372 tore down

 

[Jacob J.]

There's bolts for the muffler on a 372 down inside those tubes on the front. They're 5mm socket cap bolts. You'll need a long 5mm driver or a T-handled 5mm wrench.

Check the connecting rod bearings on the crank for play. There should be no up and down movement of the rod. A little side to side motion is ok. Check the connecting rod bearing cage and make sure it's in good shape and not cracked or broken.

 

[pinesfarm]

thanks for the help the crank is definatly ok no upwards play just a tad bit side to side

bump

 

[wi50]

good projects to learn on,

the connection rod should slide side to side when you try to slide it on the crank pin, grabbing near the crankpin. When you grab the top and try to tip or rock it side to side there will be some movement, but there shouldn't be much. It's nice to have others to compare them to, or see several saws apart and then gain knowledge of what's acceptable and what's not.

Look for any discoloring of the rod near the crankpin also. That will tell how hot it may have gotten.

I know OEM is the best parts available, but for someone learning to work on saws and tune them, the aftermarket parts do have a place. I'd rather see someone trash $100 than $300, though it takes experience to spot defects in the aftermarket parts, I'm not saying either is perfect or one kind is trash.

Chances are a simple piston, cylinder swap and you'll be back up and running.

That 650 I got from you wasn't scored, the cylinder is dang near perfect. The piston came apart and wedged. Bad news is that the rod is smoked so it's going to take some time to split the case. I've got parts on hand so when I get time I'll end up with a modded 660. It's the chance one takes, once in a while it's an easy fix, and once in a while there's a lot more to it.