I own an '86 Polaris 250 2-stroke and I can't get it started. I pull on the engine recoil starter and there seems to be a tremendous amount of compression. Could the cylinder chamber be flooded with gasoline? I use the electric start and the starter turns, but the engine does not fire. Also, while trying to start it electrically, I hear a faint hissing sound as if air is escaping.
You may have a broken ring or badly scored cylinder or something like that. This would make it difficult to pull over, and the air sound would be blow-by going into the lower end. Take the plug out and try pulling it over. If it is still kinda difficult (harder than a free-wheling engine should be) then I would pop the jug off it and check out the top end.