Bench testing a starter, does this seem right?

[rholmes69]

'03 Mahindra 2810, no symptoms of a failing starter, it just one day wouldn't crank. Made a 1/8 of a turn of the engine when the key engaged, then all lights flashed, needled bounced and when keyed off, it buzzed. Replaced battery, same symptoms. Checked the ground, cleaned, still good. Keying ignition would cause it to turn maybe one full revolution, then act like it jammed up on the compression stroke. Release key, try again, would maybe budge an inch; release try again and then it would turn maybe full revolution, repeat, etc, etc. I yanked the starter, pulled it apart, looks like brushes and armature visibly ok. Good contact on the carbon to the rotor, bearing and planetary gears spinning freely. When connecting directly on the bench, the starter turns, but it almost seems like it is slowly ramping up (initial speed is well over 100 rpm, it isn't spinning super slow, it just isn't hauling butt like I would think it would.) I am used to automotive starters wanting to just torque themselves out from under your foot. This one is cranks up and it seems like the longer I leave connected to the battery, the faster it will start to turn. I have to remove the positive lead because it starts glowing pretty red and looking like it is going to "weld itself" onto the positive lug. Bendix operates normally...

So cliff notes question, should the starter crank pretty hard when it fires up, like it would twist its way out of your hand or from under your foot? Is it normal for the starter to "ramp up" to speed? This is the same motor/starter on the Kioti DK35, 40, etc series....

 

[k0ua]

While I have no experience with the tractor starters, I have tested car and motorcycle starters and they torqued and spun up fast under no load just like you said. My first thought is your starter is draggy.

 

[TCJatko]

While I have no experience with the tractor starters, I have tested car and motorcycle starters and they torqued and spun up fast under no load just like you said. My first thought is your starter is draggy.

This.^^^^ Maybe too much or too little lube on the bushings?

 

[drizler]

Take the starter down to ye ol local mom n pop starter / alternator repair shop. Get it tested there and if need be they will freshen it up clean it out and you will be good to go for another 10 years. Buying starters/ alternators from a dealer is a horrid rip off and rebuilts from major firms tend to send them back out the door with things that are still in spec yet "almost" worn out. A starter or alternator will last the life of any vehicle with simple repairs and besides, when you trade your core in you don't have any idea what condition the rebuilt was in or how badly trashed it once was. You end up paying twice the price and getting a big unknown.

 

[Dave M7040]

I agree with drizler. Go to small local shop.
It should spin at high speed and a serious twist in your hands. Possibly segments of the armature are failing.
The local shops will recognize the starter. It is likely used on many engines and available for a reasonable price if parts have failed.
Dave M7040

 

[pat32rf]

Had this same problem with an Isuzu that we owned. Turned out to be a leaky head gasket and one cylinder would suck in some coolant due to rad pressure when hot.
Your starter sounds fine to me, but if it is allowed to crank with no load it can go above design speed and damage the armature, often with a loud bang and flying pieces....It is a series wound motor which means that as the speed goes up, the current goes down but the speed will increase far above normal cranking speed. The torque is maximum at lowest speed and so is the current.

 

[City Farmer]

Sounds like the same problem I had with my dozer. Cranked good then click, click, buzz then nothing at all. Took it to the local starter guy, new brushes and $60 later. It cranks and starts that machine like you wouldn't believe.

 

[mitch becton]

these starter are very bad to have brush and solenoid problems i see you are close to raleigh should be a rebuild shop there can help repost if you cant find one