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I actually lightly cleaned up about 70 % of the commutator before I took it to the shop.

I love those old school places that fix shit, not replace everything. A dying breed.

FJRoss wrote: ↑Sat Jul 28, 2018 9:46 pm

ionbeam wrote: ↑Sat Jul 28, 2018 8:49 pm

John d wrote: ↑Sat Jul 28, 2018 3:49 pm The starter/alternator shop didn't think there was anything wrong with the commutator either, but seemed to think the armature was the problem...

I agree with the armature being the likely cause of excess current draw...

Can they even test the armature windings with a semi-hard short across the comutator from conductive brush dust/oil/comutator dust paste?...

Any shop that does starters should have a 'growler' armature tester, it's an old school, old tech tool that just works. They should also have meters capable of measuring even very low ohms.

Growler -- Reader's Digest version: When an armature winding is shorted, it creates two circuits, one before the short and a second one after the short. The growler applies an AC voltage which makes the first circuit act like the primary of a transformer and after the short acts like the secondary side of a transformer. This causes a strong magnetization of the armature coil. When a feeler, a thin flat metal piece (typically a hacksaw blade!) is placed over a shorted armature the feeler vibrates very strongly creating a growling noise that always means the winding is shorted.

FWIW armatures can be checked reasonably well with continuity checks. There should be continuity from each section of the commutator to one and only one other section. If it connects with two sections one of the coils is shorted to another. Also check each section to the shaft and to the core plates ehich hold the windings. There should be no continuity there.

Usually I used a powered test light.

A growler is quicker and a lot cooler though, but finding one and someone who can use it is a different story.

A starter rebuild shop usually can't compete with the chain stores who rebuild by slapping somewhat capable parts together and painting it to look nice. However, sometimes the extra cost is worth the known good rebuild because a lifetime warranty on a Chinese rebuild isnt worth shit if you replace it every two months.

Okay, the new starter came in late yesterday.

Today it's all back together and I went for a couple test rides. It now starts like a champ hot and cold.

I also cleaned the butterfly valves while I was in there. Interestingly, the idle was now too high at around 1400 rpm and I had too turn the adjustment screw quite a bit to get it down to 1100 rpm.

I checked the amperage draw, but it was hard too get a reading since it now starts so fast, but I did get readings of 80, 132 and 145 amps. I know anything over 80 is not good, but it starts so good now.

The old starter is still up for grabs to the lowest bidder.

Amperage is a difficult way to check starters. Amp draw is related to load and rpm of the motor. A slow highly loaded motor will draw more amps than a faster turning lightly loaded motor. There are also things like onrush current that foul amperge readings. (Unless you're ising a scope?)

Anyway, glad you got it fixed. I wouldnt worry too much about the amp readings if it's working well.