ericm979
Super Member
Does it stop as in gets hard to turn by hand or locks up so tight you cannot turn it with a wrench?
Don't do that. It could do more damage. If the piston stops there is something keeping it from moving. Debris from a broken bearing, a piece of broken piston ring, piston ring hanging up in a port, etc. I'm assuming the spark plug has been removed so it's not running up against compression.
Did you take the muffler off and look in the exhaust port as you gently turn the crank? Pistons usually seize on the exhaust side because it's hotter.