Starter spins, pinion gear jumps up to flywheel, but, wont turn engine over. Battery well charged...??

[jpilk99]

Hi folks,

My starter has been slowly losing it's ability to start my riding mower. Sometimes it would start the machine immediately, other times I'd hear it spinning with the pinion gear not "up" into flywheel, but, after backing off the key and trying again, it would start right up. This scenario got increasingly worse over the course of a few months until now when it just won't spin the flywheel to start mower. I can turn the 'cage' on top of flywheel/engine by hand.

This starter, I believe, is the original making it 10 years old. Maybe it's just lost its mojo? Any use in taking it apart and cleaning brushes/armature?

Thanks for any advice,

Jay

 

[i7win7]

Inspect starter gear, if gear shows signs of wear(rounding off), may need replaced. If it will start after moving flywheel, may have a damaged flywheel tooth.

 

[jpilk99]

Inspect starter gear, if gear shows signs of wear(rounding off), may need replaced. If it will start after moving flywheel, may have a damaged flywheel tooth.

I think the gear looks good. Just weird that it spins when I turn key, but, when the gear gets up to the flywheel, it just stops - though I can hear the starter motor "trying" to turn the flywheel. I thought battery might be tired, so charged it for hours, even left the charger on and tried starting mower - same result. I thought I saw a little smoke coming out of the starter last week after about 15 or so tries... Again, I'm thinking the starter is "worn out", which is obviously a very non-technical condition.

 

[Liquidsilver]

When a fully charged battery gets to a certain age, it will show full voltage, but then drop to nothing when you put a load on it. Could that be it?

The thing that got me recently was a poor connection to ground. For the life of me I could figure why the big girl wouldn't crank. Replaced the battery, replaced the starter... then I noticed that some ham fisted mechanic had just run the ground wire over to a radiator bolt. Duh. When I changed that to the engine block, she cranked like a monster.

 

[ROUSTABOUT]

That's a permanent magnet motor. Take it off and take apart. Sometimes a piece of magnet chips off or maybe a whole side has come aloosened. Maybe the brushes are sticking. Make sure they move in and out freely. Tap on it and you will for sure have a magnet broke loose. Of course make sure all your connections are good. Jump at the solenoid and you bypass ignition, solenoid, and safety switches. So have everything in neutral when you do it. Sometimes all the safety switches cause it to lose a little voltage on way to starter. It was a Kubota accepted dealership fix to add a relay that was on activator wire to give solenoid enough voltage to activate it. Basically your original activator wire wasn't enough for activation of solenoid but it would easily close a relay. But I still think you need to bypass safety and isolate starter. Then you will have direction. Because if you don't know where you are going, you can't go anywhere.

 

[bearthebruce]

If the windings are failing, the motor can also spin under no-load but fail once current is required to do work. Your starter may be gone.

Safety circuits, then Battery, then starter since I guess the safeties are least cost, then battery, then the starter motor.

 

[CalG]

Hi folks,

My starter has been slowly losing it's ability to start my riding mower. Sometimes it would start the machine immediately, other times I'd hear it spinning with the pinion gear not "up" into flywheel, but, after backing off the key and trying again, it would start right up. This scenario got increasingly worse over the course of a few months until now when it just won't spin the flywheel to start mower. I can turn the 'cage' on top of flywheel/engine by hand.

This starter, I believe, is the original making it 10 years old. Maybe it's just lost its mojo? Any use in taking it apart and cleaning brushes/armature?

Thanks for any advice,

Jay

Suspect the battery first.

As mentioned, low voltage under load is the death knell. Put a meter on it, or turn on the headlamps and see what happens when the starter is hit. (of course this test is not possible with a load shedding relay system)

PUT A METER ON IT!

If the voltage is good, then the starter motor is suspect.

I assume the engine DOES TURN FREELY. If a leaking carb has flooded the crankase with fuel, the engine could be hydro-locked.

 

[Xfaxman]

I agree put a meter on it! The negative lead on the negative post of the battery, not the cable clamp. The positive lead on the positive post of the battery, not the cable clamp.

Watch the meter when the starter stops turning and write down the voltage. Move the meter leads to the frame and positive on the starter post, not the cable. Try to start, watch the meter again and note the difference.

This will show where the problem is.

 

[jpilk99]

One additional element here: The 'cap' at the top of the gear shaft (with red arrow in pic) keeps spinning while the pinion gear stuck in the flywheel. That tells me that the inner side of the pinion gear is "stripped". The cap should spin/rotate at the same rate as the gear, shouldn't it. So if the shaft/cap is spinning with the gear frozen in the flywheel teeth --- that seems to point to there's something wrong with the equipment of the starter; specifically the pinion gear.

Thoughts?

 

[beenthere]

One additional element here: The 'cap' at the top of the gear shaft (with red arrow in pic) keeps spinning while the pinion gear stuck in the flywheel. That tells me that the inner side of the pinion gear is "stripped". The cap should spin/rotate at the same rate as the gear, shouldn't it. So if the shaft/cap is spinning with the gear frozen in the flywheel teeth --- that seems to point to there's something wrong with the equipment of the starter; specifically the pinion gear.

Thoughts?

Which model John Deere lawn and garden tractor is this?
Doubt 10 years would be a worn starter.