TO-20 Starter issues

mskobier

New User
All,
I have a TO-20 that I did a 12v alternator conversion to. Within a couple of days of getting the alternator belt issue resolved (previous post)the original 6v starter died. The symptoms were as follows: the starter spun up nicely, and the tractor started right up. After a few days of testing various tractor components, the starter acted like the battery was dying, then stopped turning completely. The starter never even got slightly warm. No indications of current flow to the starter. So I figured that the old original starter was on its last legs anyway, and ordered a replacement from -bay. That one arrived, and I installed it. Tractor starts up nicely, but within a few days, the exact same symptoms happened and the starter would no longer turn over. This starter never got warm either. Now I am annoyed. So thinking the 12v into the 6v starter was too much for it to handle, I ordered a 12v one from this web site. Thinking that a starter rated for 12v should work without any issues. Well, it didn't last more than a week either! Now. I'm really upset. I am not abusing the starters. I limit any cranking to no more than 5 second at a time with at least a minute between tests.

So today, I took the two original 6v starters apart, and here is what I found. The original starter has a broken wire that attaches to one of the brushes. The crimp spade had actually broken where the screw attaches it to the brush. The comutator is in good shape, with not significant pitting. The brushes are in useable shape. I'll get a new spade connector for it from a rebuild shop in the near future.

Now on to the "new" 6v starter. When I opened it up, the comutator was severely pitted, with no continuity through the starter. After cleaning up the comutator on the lathe, and putting the starter back together, and reinstalling in the tractor, it turned over about 3 or 4 times, then stopped working. So I pulled it apart again, inspected it and found that one of the ground brush holders was sticking and not making good contact with the comutator. I tweaked the brush holder with a pair of pliers until it moved freely. The face of the four brushes were in pretty bad shape too, and worn on an angle lengthwise from where they had been installed crooked.. So I took all four brushes out one at a time, and flat filed the face of the brush to clean up the pitting. I then left all four loose and re assembled the starter armature in the housing. I left the positive brush connections off until I had ensured each brush was seated squarely to the commutator, then tightened all connections. I then bench tested the starter without a load to let the brushes seat back into the comutator. I hooked up an amp meter to the starter during this testing and found the starter pulling approx. 65-75 amps, no load. I ran this test for approx. 30 seconds at a time for about an hour. Giving a few minutes in between for the starter to cool downa little. At the end of this testing, the starter was fairly warm. The brushes seated into the comutator nicely and the comutator smoothed down nicely too. Not perfect, but serviceable. I then put this starter back into the tractor, and tested. The starter works perfectly, with no hint of slowing down or stopping. So I have at least repaired one of the starters. The original will need a new spade connection.

The 12v version is setting on the shelf waiting for the seller to reply to the email I sent in regards to an exchange. To be perfectly honest, the 12v starter really acted like a 6v one does. It turned the engine over about as fast as the 6v one running on 12 volts does. I would have expected the 12v version to be a bit faster than a 6v one on 6 volts, but not as fast as a 6v one on 12v. So I'm thinking I was sent a 6v one in error. Either way, the starter has died, and need to be replaced. So, that details the starter saga on my TO-20. Hopefully, this repair will have corrected the starter problems.

Mitch
 
You can run a 6V starter on 12V. Your just not suppose to crank the life out of it. With a properly tuned engine this should never be a problem. I currently have about 80 hours of 12V on a used 6V starter that came with the wife's tractor when we got it. Yes, I have cranked it excessively at least twice, three times...four? So far. Just stubbornly refusing to admit that the machine has a problem beyond the ability of the starter over coming it. Sound familiar??
 
Bruce,
Thanks for the reply. I have run 6v starters on 12v before with no problems. I understand the limitation of not cranking it excessively. In this particular case, I was being careful to limit the cranking duration. No longer than about 5 seconds at a time. The original starter failed due to a mechanical failure, broken spade connector. The second was a manufacturing defect as a couple of the brush holders were hanging up which caused the arcing which damaged the commutators and brushes. The third starter was supposed to be a 12v starter. It exhibited the same failure mode as the second 6v starter. Even on the 12v starter, I limited the cranking to no more than about 5-7 seconds. None of these failed starters exhibited the slightest bit of warmth when they stopped working, so they were not overheated.. Anyway, the new (rebuilt-TSX458)carburetor arrived the other day. I plan on installing it today. Then I get to start re-assembling everything. I still need to pick up a set of studs to be able to mount it.

The main reason I did the 12v conversion was because the water pump pulley split, which destroyed the belt and damaged the generator pulley which would need replacing too, Also, the 6v generator was continuously having to be re-polarized. I had replaced the voltage regulator a couple of times trying to resolve the issue. So in short, I was tired of futzing with the 6v system.

MItch
 
I did the 12V conversion on the wife's TO-20. In some ways I possibly should have stayed original. One being the cable drive adapter genny running the proof meter. Currently I need to rewire the genny either for 12V or get a 3K tack to mount up. Just have not decided what it is I will do e-v-e-n-t-a-l-l-y.
That is longer than a round tuit.
 
Bruce(OR),
I know what you mean by the long round to its!. The water pump pulley split mid summer of 2014. Just a few months ago I started in on the repairs. My TO-20 does not have a tach, or even a place for one. Its a 1949 model and all it has is an oil pressure gauge and an amp meter. I've thought about using one of the automotive tachs or even one of the little electronic ones. I'll figure something out eventually. I did get the new carb installed today. I haven't had a chance to tune it yet, as the fuel tank is not installed. I did some much needed maintenance to the throttle linkage today too. I uses a cork friction disk from the lift control to replace the friction disk on the throttle. I need to verify the timing again since I had to remove the distributor to replace the starter.

By the way, the repaired starter seems to be working fine. The tractor doesn't seem to start as quickly with the new carb. Hopefully, once I get it tuned, that will resolve itself.

Am I correct in the (OR) in your name a reference to which state you are in, specifically Oregon? I'm Located in the Tri-Cities area of WA.

Mitch
 
Your travails w/ your starter sound eerily like mine. I have a TO30 that I've been fighting w/ all year w/ starter issues. I had one older one fry on me this spring, didn't think anything of it since starters eventually die, so I ordered a 12V one online. Got a handleful, maybe 6-8 starts out of it before it stopped working. All I would get is a solid click at the relay/solenoid that connects my starter to the battery. I took it apart, noticed I had a couple frayed wires. Thinking it was my fault, and mostly not knowing squat about starters, I ordered another one! After installing this now 2nd new one, again I got 6-8 starts out of it before it quit working and again, I'd get this solid click at that relay/solenoid. Just like before, it never sounded like the starter wanted to engage at all. I took it off again and this time, wised up and took it to get tested. Autozone said it was defective; their first test showed it to spin but not fast enough, the 2nd time, it didn't do anything. Knowing a starter shop right down the road, took it there, and couple days later, they tell me it tested fine. Put it back on tractor, and voila, it engages. After a few more cranks on it, while trying to diagnose other issues w/ the tractor, again, it fails to engage. I'm at my wits end with this thing I tell ya! I took it back off and called this site, and all the guy will tell me is that the manufacturer will test it and if it tests fine, they'll bill me $200 to replace it! No way! I really think its defective and this manufacturer turns out turd starters. Problem is I'm passed my 30 day guarantee from YT, but not past the 1 yr manufacturer warranty.
I took the original starter I had and am now getting that rebuilt. I hope this solves my problem b/c YT sure hasn't been helpful at all.
 
Golferjones,
Yep, it sounds like the same type of issues I am having. Fortunately for me, mine failed it a short period of time, and the folks at YT are taking care of the issue. Here is what I found with the first new starter that failed. Whoever assembled it did not have much quality control. It looked like they just installed the brushes, then bolted it together. After I has repaired the damage to the commutator and brushes, and a gentle tweaking of a couple of brush holders, and a through running in, the starter seems to be working fine. What happens when the brushes are not installed properly or the brush holders are hanging up, the brushes and commutator gets chewed up by the large arcs caused by the bad connections. This only makes the problem worse. Remember, these starters are probably seeing somewhere in excess of 350 amps during the cranking cycle. After I repaired the damaged starter, I was seeing a steady 65-75 amps of draw with no load. This is roughly what it should be pulling. I need to dig out my big amp meter to see how much current it is pulling in the tractor. I would bet the 6v starter operating at 12v will be easily over 350 amps. I think a proper 12v starter should be pulling about 250 amps. Anyway, hopefully the local rebuilder will do a good job of repairing/rebuilding your starter and your troubles will be over.

Mitch
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top