Some people have those problem speacialy on a brand new engine, of what i seen they used hair drier to heat up the engine first before they fire it up. this way it will expand the sleeve. also make sure that the piston is on the buttom when your not using the trck cos when the sleeve cool down it will go back to thightness so it will hold the piston and it will give you hard time to pull that cord again. Also it is better to use after run oil instead of
w-40 oil. so go to a lhs buy one make a couple of drop specialy after run.