1 Answer

At the top of the fly wheel on the mower there is a small round housing that is attached to the fly wheel by three screws. It has a stamped sheet metal cover and under that cover are three steel balls, When you pull the cord the centrifugal force spins the balls outward and they lock the pull cord mechanism to the fly wheel and this allows the pulling force needed to start the engine. When the engine starts the initial start up speed of the engine slings the balls outward and disconnects the pull cord mechanism from the fly wheel. The problem that is causing the engine to yank the cord out of your hand is that the balls have become stuck due to dry grease or no lubrication whatsoever. You need to get to that balls and add some lubricant. 

If you have a new mower you will be looking for pins that come out when you pull the cord. If they get stuck, the same problem as above happens. 

Colleen

Then your compression could be off. You may need to take it to have the compression checked.