Starter Motor Overhaul - Y385T Engine

[aesmith]

Hi,
The tractor is a Siromer 304 which I think is virtually identical to the Jinma 254. More to the point, the engine is the Y385T.
Has anyone carried out an overhaul of the starter motor for this or similar engines. The problem that I was having was really sluggish turn over, almost as if the battery was flat or weak. In fact for a cold start it sounds as if the motor isn't going to turn over at all. Using a known good battery didn't help. After checking all the connections (which were OK) I decided to have a look at the starter.

What I found was that the commutator and brushes were all gunged up with greasy grey muck to the extent that you could hardly see the copper colour. I've cleaned all that up and the commutator looks OK now, there's plenty of meat on the brushes and the springs and connections look OK.

This seems to have improved things but it's early days. Is there anything else that would be worth checking?

Thanks, Tony S

 

[piper184]

Sounds like you got it. Just clean everything, blow the dust out of the windings, etc. Then if it moves, lube it. Make sure all the electrical and mounting bolt points are clean and shiny metal to metal contact.
It is just an ongoing maintenance thing.

 

[aesmith]

Cheers. The real test will be a cold start after the tractor's been sitting a couple of days. Fingers crossed. What it was doing before was a sort of groan as if it wasn't going to run, followed by turning sluggishly then a bit faster. Trying to convince myself I have fixed it I was thinking if contact between brushes and commutator was poor maybe that was the very slow initial response, improving a bit as it turned and wiped the surfaces.

On an older tractor the commutator had poor segments so it depended where the motor had stopped, this never really stopped it working but when I swapped it for a recon starter there was a big difference. If this starter seems to be OK I might strip it again and check continuity on each segment of the commutator, although they look OK.

 

[SandburRanch]

Sometimes the Mica needs to be under cut , but that's usually on old equipment with lots of starts . If the muck wasn't cleaned from between the commutator bars well enough that could caust a problem . A tool for that can be a hack saw blade with the tooth set ground off . Greasy gray muck seems a little strange and makes one wonder where that's coming from .

 

[piper184]

The symptoms you described are the same as I had, although there was no grey muck in mine, just dirt and brush powder. The real culprit was the binding caused by dry bushings. A little white lith. grease took care of that. The tolerances are not too critical in this application but a dry bushing will stop it, especially cold. At about -30F even my well lubed starter complains. In that case I blast it with a little heat to expand the metal a bit so it will spin. Also the brushes had mushroomed over a bit making them wider and possibly able to span two segments so I gently filed the edges down to width and gave then a slight chamfer. Seems to have worked.

Pulling the starter should be on some kind of summer maintenance schedule, but always seems to get over looked. Kind of like the 20+ year old garden tractor that refused to start last summer. Starter was bone dry. Cleaned and lubed and good for another 20 years!

 

[Johnny P]

Hi,
The tractor is a Siromer 304 which I think is virtually identical to the Jinma 254. More to the point, the engine is the Y385T.
Has anyone carried out an overhaul of the starter motor for this or similar engines. The problem that I was having was really sluggish turn over, almost as if the battery was flat or weak. In fact for a cold start it sounds as if the motor isn't going to turn over at all. Using a known good battery didn't help. After checking all the connections (which were OK) I decided to have a look at the starter.

What I found was that the commutator and brushes were all gunged up with greasy grey muck to the extent that you could hardly see the copper colour. I've cleaned all that up and the commutator looks OK now, there's plenty of meat on the brushes and the springs and connections look OK.

This seems to have improved things but it's early days. Is there anything else that would be worth checking?

Thanks, Tony S

Hello Tony. I had a problem with my starter. I dismantled it and had to do some re soldering of wires that had come dodgy. One one occasion I cleaned the point where the battery earth strap was connected to the chassis and gave it a good clean and that did the job then.

 

[piper184]

Yup, cleaning and lubing the starter is just routine maintenance. I do it whenever the starter "seems weak".