Craftsman Chainsaw Repair

I have a Craftsman 358.350202 Chainsaw with a 20" bar and 46cc engine. It's acting like it has way too much compression. It's super hard to pull the pull chord. So hard that I can't pull it fast enough to generate a spark. These are the things I've checked-- the cylinder and piston are in perfect condition, all the bearings in the crankcase are good and have no play in them, the flywheel is in the rite spot and timing is good, the shear pin is good for the flywheel, there is no clogging in the exhaust port or muffler, the carb has been rebuilt and its not vapor locked. I've cleaned all the carbon build up off the piston and combustion chamber. I've checked the pull bored assembly and its in good condition and working properly. I've tried with the muffler and carburetor on and off the saw. The only thing that helps is when I take the spark plug out. With the spark plug removed it turns over with ease and with no metal on metal noises. The only thing I can see that might've the problem is that when I opened up the crank case and pulled the piston out there were no cylinder inserts. The parts diagram in the manual and every diagram I could find online doesn't show it having any. But every chainsaw I've ever opened up has had those little inserts. I have no clue what there for but I assume they move the air around from place to place when on the intake and exhaust strokes. If anyone has any info or could lend any type of help for this I would greatly appreciate it. I'm at the end of my knowledge and really need to get my saw running. Thanks in advance.