Chainsaw Repair

I have never seen a piston for a 330,3450,3500,3750 that did not a have a pin in the ring groove so that the ring cannot rotate.   

This ^^^^^^^^^


We need pics of what you got going drum

Ah, I see where the confusion is now.  When speaking of pin offset, I am referring to wrist pin.  Some engines have offset wrist pins, i.e. not in the center of the bore, to reduce piston slap.

When referring to these PoulanPro 330's, I am saying of three different pistons, (two from 2007),one has the ring gap pin on the intake side and the '07's have the ring gap pin on the exhaust side...Why?

They can apparently be installed either way.

Ring gap needs uninterupted cylinder wall, correct?

With the 3 different Pistons did you happen to notice if there was any difference in the cylinder ports.

Saw went back together yesterday.  Swapped piston with one that was originally run with ported cylinder.
Tore it down to replace crank seals, but took it completely down to crank in hand.  Seals looked fine,... should, being new. Reassembled and sealed with permatex aviation.

Any running issues have vanished.  Running strong.

Also built a pump drive puller so I didn't have to wait for shipping.   Used a 1/2" plumbing union, a 1/2 -3/8 hex (required internal grinding past threads), and a fine thread G8 bolt.