Lawn mower engine Bendix drive question

[Donald]

I am working on Bendix drive from Husqvarna riding mower. The Bendix drive had mouse nest material wound around the Bendix drive. Cleaned it all out with a toothpick and tweezers.

The shaft is nylon.

Question is should the spring push the gear back down when the starter is out and I move the gear up by hand and let it go?

No lubrication on the shaft since it's nylon.

 

[mk378]

Bench test the whole starter by jumping to a battery. Yes the gear should go back down by itself.

 

[andyd]

Thankfully, The starter on my sit down, 11 hp B+S hasn't acted up in ages. I could probably figure it out if I had it out. Rotate the gear out is done by motor, overcoming the spring. Motor stops , spring should be enough to push back toward the motor. I'm guessing if the spring won't push, then you haven't got it cleaned out enough. There should be a snap ring or some sort of geezus clip holding the starter drive on. On the other hand, the spring is pretty wimpy. Maybe it just acts as a guide as the gear is thrown off. Maybe exercising the throw action a few times will free it up. Put it back on and see what happens.

 

[Donald]

Spring feels very wimpy.

 

[Linctex]

The speed of the flywheel will also throw the gear "down" away from the ring gear.

 

[mk378]

What brand is the engine? As andyd said, the Briggs ones operate by a combination of a wimpy spring, gravity, inertia, and luck.

 

[Donald]

Briggs engine.

Applied power to the starter while on workbench. The starter turns just fine, but the gear does not spin up.

 

[Lubener]

Originally Posted by Donald
Briggs engine.

Applied power to the starter while on workbench. The starter turns just fine, but the gear does not spin up.

If the shafts spins, replace the bendix. A little graphite on the starter shaft when installing will do it.

 

[mk378]

Make sure it is turning the proper direction, i.e. you didn't reverse the battery. The initial starting inertia causes the gear to go up, but it may not go all the way to the top. When it is on the engine, the gear at halfway up will catch in the flywheel and be driven the rest of the way up.

Like most parts of a Briggs, it has been very carefully engineered to do only what it absolutely needs to do, and not a single bit more.