Craftsman Tractor Starting Issue

[lefty2cox]

Model: 917.271760 Serial: 091302D007110
Briggs Model: 31R977-0043-G1 / 160218ZA

Starter spins but the bendix does not pop up and engage. If I spin the bendix by hand everything seems to function properly and move freely. I have 12.8V at the battery, which is new. Voltage drops to 11.8v at the starter when turning over. Wire from bat positive to solenoid shows less than 1 ohm resistance. Same on wire from solenoid to starter. Same for bat negative to the engine. All connections are tight. It spins but just won't engage. I'm thinking I have a bad starter. Am I missing anything? Is 1 volt drop normal at the starter. Is 11.8v enough to get the starter to engage the flywheel? All questions bouncing around my head right now. Any advice / help is appreciated.

Thank you.

 

[Rivets]

Probably need to replace the starter drive. If my memory is still any good, I believe the part number is 593934, but you better check with the repair shop you use for parts.

 

[slomo]

Am I missing anything?

Yes you are. You can only test circuits under LOAD. 1 Ohm means the pipe is open. Under full load is the real test. Means the pipe can flow at max amp draw like normal circuits run at.

 

[slomo]

Is 1 volt drop normal at the starter.

No such thing as normal drop levels. You do not want your battery voltage to go below 10.5v DC while cranking the engine. Example, if while cranking your battery drops to 8 volts then you need a charge or a new battery.

 

[slomo]

Is 11.8v enough to get the starter to engage the flywheel?

Yes it's fine.

 

[lefty2cox]

Probably need to replace the starter drive. If my memory is still any good, I believe the part number is 593934, but you better check with the repair shop you use for parts.

That's the number I came up with as well on the briggs site.

 

[lefty2cox]

Yes it's fine.

Can I assume that if 11.8 is adequate for the starter to operate normally that the starter is the culprit? In other words, if the starter was looking for a certain amperage from the battery and I had a problem with resistance in the wiring, wouldn't there be an unacceptable voltage drop due to the restriction? Just trying to wrap my brain around it.

 

[ILENGINE]

This may sound stupid but make sure that you didn't connect the battery backwards. It will cause the starter to spin in reverse if it doesn't cause other electrical failures.

 

[lefty2cox]

Stupid falls right into my wheelhouse. So thank you. I'm not near the machine now but I will verify.

 

[lefty2cox]

Yes you are. You can only test circuits under LOAD. 1 Ohm means the pipe is open. Under full load is the real test. Means the pipe can flow at max amp draw like normal circuits run at.

Should I take an amp measurement on the positive starter wire? If so, what amperage am I hoping to see?