Scag tiger Cub / Briggs Engine wont tunr over when the Hydro belt is on? Help?

[Bill in CT]

After finishing a fall clean up I drove my tiger cub into the trailer and off to the next job. Upon arrival the starter would turn the engine slowly a couple revolutions and the solenoid clicked. After changing the battery and solenoid. Removing the starter and bench testing and removing the clutch...I found it will turn over and start every time with the hydro belt off. I turned all four pulleys (2 hydro, tension and guide pulley) both directions with zero resistance or indication of a bad bearings.

Any thoughts ? I'm stuck.

I'm thinking the starter might be weak? Not sure how to test a weak starter? The bendix flies out on the bench and installed starts the engine with the hydro belt off.

It wont start with the hydro belt on?

 

[bertsmobile1]

99% of the time a slow starter is due to the valve being out of adjustment.
The other 1% the battery is flat :confused2:

Seriously check the starter by using a pair of jumper directly from a known good battery to the starter motor.
Motor spins fine then have a good look at all the electrical leads & connections.

Starter turns fast / slow /fast / slow then adjust the valves, gap will most likely be too big on inlets.

Valve lash OK then remove plugs and turn engine over by hand watching the valves making sure they go fully in and come fully out in sync with the piston.

Mower starters are not particularly strong so the combined effects of dirty connection & insufficent decompression combined with the tiny load from the tranny belt is just more than they can move.

 

[mechanic mark]

Check all ground straps & cables by hand making sure they are tight & secure, especially from engine to chassis.