B&G lawnmover makes knocking noise when I try to start?

Question

It sounds like the blade is hitting something when I pull the cord, but the blade is moving freely. Themower used to start with this noise, but now it just will not anymore. Help would be greatly apprciated.

Answer 1

Sounds like a broken shear pin,the mower will not start ever until it is replaced.

Answer 2

DANGER-DANGER Before you rotate the blade by hand be sure you disconnect the spark plug wire and keep the wire away from the plug! Removing the spark plug is better.

Accidental starting could produce "unfortunate" results!

Answer 3

Check compression, as could be a stuck valve.

Answer 4

I agree with the other post but first tip up the mower and rotate the blade through a complete revolution. It could be tapping something just enough to have this happen. {had this happen to me}