The Stovebolt Site Forums The Shop Area The Electrical Bay Sluggish 12V Starter

Hello folks..it's been awhile but I'm still on this side of the daisy's, and have a question for the brain trust.

I have a 12 volt starter that doesn't seem to spin like it should after it's installed. The application is a Continental F124 engine in a forklift.

I have installed new brushes, turned the commutator, undercut the Mica, bushings are great, battery is brand new, positive cable is new. I took the starter to a auto electric shop where they growled the armature and put some fiberglass tape on a suspicious brush wire and gave it a clean bill of health. The only thing not done was a negative cable replacement.

When I had the starter on the bench I pulled the solenoid apart, flipped the copper disc and turned the post to virgin territory. If I attach a charger and hit it with 200 amps it will buzz right over, other than that it just doesn't crank well at all.

I attached a current draw gauge and when cranking it indicated about 250 amps.

The forklift has only inches of ground clearance so removing the starter is a big deal..especially for a 75 year old wimp like yours truly.

What haven't I done, what have I done wrong or what am I overlooking?

Thanks,
Stuart

Replace that negative cable. If it's got any corrosion at the battery, it may also have corrosion inside under the insulation, turning the copper into green goo that does a terrible job of conducting electricity. You can check to confirm by using a jumper cable in parallel with the existing cable so the load is shared.

And this pertains to a Stovebolt truck how? Just asking for a friend.

Both cables carry current, they both must be in excellent shape.

Ed

Tell your friend that it's a 1951 Chevrolet 1/2 ton forklift...very rare!

Stuart

Get a couple of new battery cables made up from #1 or larger welding cable (not coarse strand battery cable). Make the ground cable long enough to attach as close as possible to the starter housing- - - -ideally, under one of the bolts that attaches the starter to the engine.
Jerry

Our 1941 Ross came with a four cylinder L head Continental which we replaced with a 305 sbc V8. Kept the flywheel, bell housing, and 6 VOLT STARTER of the Continental and mounted on back of the sbc. What is pertinent here is yours works fine with a booster so you might consider replacing your 12v starter with a 6v one. Do NOT recommend for this for an engine that takes several minutes of cranking before it fires but on one that fires right up a 6v starter will last for years. A 6v on 12v really zings over. My 37 Buick also has a 6v starter on 12v and has been so for 40 years.

[img]https://i.postimg.cc/TpGZ4V2x/IMG-5251.jpg[/img]

This is a senior member in good standing.
Please move this to the Fork Lift Starter forum. Problem solved. Thanks.

Fix the grounds, that was prolly the whole problem... but at least the starter should be in good shape now!

Also, consider this thread the fork lift starter forum, since I'll assume that the forklift uses a GM starter.

Well thank you gents for your input as well as allowing the GM starter (?) space in the forum.

I'll give the big fat cables a try, clean up any fungus where they attach and see what happens. The 6 volt starter on 12volts sounds interesting, but finding one to fit this application could be a real toughie I'm sure.


Stuart

Well, heck. Two big fat cables..the negative a #2, fully charged battery and clean connections all over and the stupid starter isn't real frisky. Sometimes it spins the motor perfectly, then the barely moves it at all. I think there is something funky with the starter but don't know what. All the segments of the comm check out and, although I'm not sure what the growler checks, the electric shop supposedly checked that and I'll assume it was OK. I installed new brushes, but let them seat themselves.

I wonder what else can make a starter spin with vigor then barely move at all. It's like there is a dead or weak spot where it stops sometimes.

Stuart

A growler checks for unwanted circuits in the armature, ones that create induced current that opposes the rotation of the armature. When an oscillating magnetic field is induced into the armature core by the growler, if there's a copper-to-copper "short" in the windings, a hacksaw blade or other thin steel strip will vibrate when it's passed over the armature. A "ground" is an unwanted copper-to-steel circuit, and it's found by touching a test light to the commutator and the shaft. A final test is for continuity, done by touching the test light probes to adjacent pairs of commutator bars all the way around. If the armature passes all these tests, it's good. I'd recommend looking for a loose or corroded grounded brush holder that's making intermittent contact with the end frame or housing, which would explain the good and bad performance at times. If somebody has done a really good job of painting a "rebuilt" starter, that can also interfere with current flow between the components, and/or the bell housing.
Jerry

Jerry,

Thank you for that.

Stuart

Just out of curiosity , is this a freshly rebuilt engine ??

John

John,

No, not fresh at all, but in great condition. The current draw seems to be up there, but the engine isn't new and tight so that is part of the question. I used the machine today and it started nanoseconds after I hit the key, so I'm going to take potluck and call it a done deal.


Stuart

Stuart, how is your starter working? Is this problem solved?

The forklift starts, but it's touch and go with the starter. There is just flat out something wrong with it. New big fat cables, new battery, new brushes on a polished and undercut comm..good armature bushings, etc. It growled fine but it's obvious there is something wrong as it spins great sometime and barely chugs on the next try.

The machine is not often used and I have other fish to fry..so, it's not solved but short of replacing it, I've lost interest.

Thank you for asking.

Stuart

Many starters have a bushing in the flywheel end, when that bushing gets worn, the shaft is off center causing the symptoms you describe. Easy to replace bushing.

Ed

Ed,

I wish that was the problem in my case...but not so, sir!

Stuart

Welcome back Stuart. Get tired of chasing all the pretty girls and decide to slum it for awhile??

I was wondering when you were going to pop in and rattle my cage!

Too old to chase anymore..just sit on the park bench and watch them go by..with pink hair, rings in their noses and tattoos on the back of their calves..things are real different these days!

I hope you are doing well in these tough times, Tiny.


Stuart

Good to "hear" from you, Stuart
You were/are a valued member of the "brain trust".
These days, I trust my brain but I cannot trust my dimming memory.

Atomarc Watch how you talk about those 75 year old fossils !! They know a lot LOL !!! those starters will work like they should on 12 volt !! Have done it since 67...really whip it over

Tim,

Thank you for those kind words, nice to hear from you as well. I was in touch with Ken Brown (GMC) the other day and your name came up..he referred to you as 'one of the good guys' and I heartily agreed.

Stuart

Turned the commutator, undercut the Mica, growled the armature and put some fiberglass tape on a suspicious brush wire, flipped the copper disc and turned the post to virgin territory.

Every one else seems to be keeping up. At first I thought your were sending us on a snipe hunt.