Small Engines (Lawn Mowers, etc.): Mcculloch Chainsaws, diaphrams, cylinder wall

Question
I have a newer 32 cc mcculloch chainsaw that will not start.  It will not even fire at all.  I have rebuilt the carb with all new diaphrams, needle valve and everything.  Replaced the spark plug and fuel filter still nothing.  The compression is 52 psi ( not sure what it supposed to be )  I just don't know where to go from here.  The mixture screws are set at 1 1/2 turns out.   Any ideas?   I do have a good spark, and I can tell that there is fuel getting to the combistion chamber.   Please help!!  Thanks

Answer
The compression is way, way too low.  Remove the muffler and carburetor.  Use a flashlight and visually inspect the piston and cylinder.  If you scoring, scratches on the piston or cylinder wall the engine is toast.

What is the model number of the saw?  There are only a couple of McCulloch saws that are worth rebuilding.

Let me know what you find.
Eric