Small Engines (Lawn Mowers, etc.): lawn mower, starter clutch, crankshaft

Question
QUESTION: If the pull chord will not pull back but can manually turn the mowing blade and hear the sucking sound  -is the shaft bent?  Changed blade and air filter earlier this season -mower 9 years old.

ANSWER: I don't believe this is a sign of a bent crankshaft, but I really don't have all the information needed to diagnose this problem. When you say the rope won't pull back does that mean it won't pull out or won't go back in?

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QUESTION: It stops on pull out  goes back in fine - pulls out about 4 inches not enough to crank the engine. Never had this happen  with mower. all else looks ok.

Answer
The only way the crankshaft gets bent is if you hit something, so if you have, it could be bent. One possibility for your problem is gas has mixed with the oil and is in front of the piston, to diagnose this, remove the spark plug and pull the rope. If the rope still doesn't come out, the rope may have retracted back in and got wound around the starter clutch on top of the flywheel.