Last winter my cousin asks me to order up a piston and cylinder for a 372xp, as he found one for sale that had been at the local dealer that was blown. So I ordered up what he wanted and sure enough he brought over a mint looking 372xp sans muffler(mechanic at dealers signature, always something missing from what he can not repair, not the first time I've worked behind him) so I can see instantly, a perfect looking piston, hmm. I also notice a piece of paper that was torn off between the carburetor and the manifold, upon removal, noticed it was a feeble attempt to block it off to pressure test, one could see the impression on the paper that it had missed its mark. So I dug through my junk pile found a muffler, did a proper pressure/vac test, which it passed. Noticed some tygon line in place of the impulse line was kinked, as there is an offset there. replaced it with a proper one and the saw fired right up and ran like the new saw that it was. Felt real bad for the man who sold his saw for $140.00 and bought a brand new one, as the only thing that was "blown" was my mind. My cousin however was ecstatic, and didn't even mind that he did not need the new P&C that he just bought.