Here is a photo

That's an old old mower. Probably a plastic gear or pawl is broken in the assembly. I've never seen one of these but they are similar to the old Lawnboys about 40 years ago.

If you do get it fixed, take some time to blow the dust off the motor with compressed air. it will run cooler.

What you have is an LAV40 series engine with an "Impulse" Starter system.

The starter is Tecumseh part #590408 or 590378.

Be hard to find one. But with the information and part numbers. You may be able to track one down. These engines came with (If I am thinking correctly) 6 different types of pull starters and two electric ones over the years.

EDIT: I forgot about the ones that had a crank starting system. You wound the starter spring with a hand crank then released the tension on the spring and the engine cranked over.

This post was edited by hippy on Fri, Apr 25, 14 at 20:12