There's other things to look for on no-starts, but because you described difficulty pulling it over, I think we need to find the source of this resistance. Since it pulls over easier with the plugs out it sounds like a compression related resistance. This can be hydraulically locking cylinders from an excess of oil or coolant in the cases / combustion chambers from a leak, or possibly a blockage of the exhaust system... but its difficult to diagnose through a keyboard.
To run with, and check for what I initially suspected (cases full of oil) here's what I would do:
-Remove spark plugs, tip sled on it's side or even a little beyond, pull the cord and see if a large amount of oil comes out the plug holes. This will only prove that there is excess oil in the cases.... or not.
Did this engine get 2 stroke oil dumped in it as end of season maint last spring?
Is it possible too much was poured in?
Are you pretty sure the oil bottle level is lower than it was when you parked it in storage?
Is the coolant bottle still full?
Checking for center crank seal leaks is best done with a leak-down tester, but some do it by filling the oil bottle and letting the sled sit and see if the level drops.
