update to busted starter

pooch

Well-known member
woo hoo, new shaft in and runs fine.

see pic, the rear bolt holding spring locating tab was already broken off.

This could have been one of my first problems with the end dog moving back, but near my last attempt before it broke, I put a dob of weld on dog.

Anyways, I drilled/tapped a new thread opposite the spring bolt and put a proper locating TIGHT grub screw (bolt) into shaft so dog cannot ever move no more.

I measured in and out pinion engagement and made it a bit more tooth contact than it had before, so I put the grub a few mm closer to armature.

(Don't go by pic as to how far the shaft is sticking out of dog, the new shaft IS a bit longer than the old busted one.)

There was talk on another post about shimming the starter housing 5/32 inch, but this would upset the locating shoulder in bell housing, then others said to cut a new keyway and make a new locator hole or weld up locator and move hole using existing keyway.

Maybe my method of drill/tap a new locator position and grind off end of spring bolt is easier?

Just tested about 30 times and fine so far.

newshaftstarter.jpg


On 12 volts, it did get the occasional slighter larger thump in.

I am not overly happy about the 12 volt stress.

I had a question on the other post which didn't get an answer.

It was in reference to a modern starter I had and it was only working on 2 out of 4 brushes and was going half speed like a dead battery.

I asked if I could remove 2 brushes out of the A starter to reduce power to armature.

Well, I decided to experiment and pulled ONE brush out, which I think would cancel the other brush out too...(dunno).

I think it seems to be easier on engaging, although speed seems similar.

Before I experiment more and maybe pull the other side brush, (if indeed I even need to), what are your thoughts?
 
I didn't know you were using 12 volts. Good luck on keeping a 1/2" starter together with 12 volts. A longer thinner starter cable would reduce the starter current some.
 
Any idea about running with only 2 brushes, Tom?

I will experiment with winding my own thinner long resistor cable to starter as well.
 
I did lots of mucking around on the 12v starter setup,tried taking the brushes out of the circuit,no diference,BUT what DID was to put a resistor in the starter feed wire,this I made fron a 12 gauge arc wel;ding rod with the flux chipped off, I tried two joined ,that worked realy fine on the speed but you only got one start before the wire heated up and let no current through,with only the one you get three to four goes at the start before the wire heats up and stops the current flow,one thing you MUST do is take the feed to the rest of the cars electrics from the bat side of the resistor.
Lawrie
 
Tom,
I have 12 volt systems on two of my Model A's.If you use the V8 starter drive,they will not give problems,at least mine haven't. James
 
I did lots of mucking around on the 12v starter setup,tried taking the brushes out of the circuit,no diference,BUT what DID was to put a resistor in the starter feed wire,this I made fron a 12 gauge arc wel;ding rod with the flux chipped off, I tried two joined ,that worked realy fine on the speed but you only got one start before the wire heated up and let no current through,with only the one you get three to four goes at the start before the wire heats up and stops the current flow,one thing you MUST do is take the feed to the rest of the cars electrics from the bat side of the resistor.
Lawrie




What diameter is a 12 G rod?

I did a search but got no answer.

***********************************

Update, I found a welding rod 1/8th inch diameter.

Using a single length, it does reduce the current to an acceptable level.

Now, to find an insulated holder to wind a nice compact resistor into and bolt it to the outer side of the battery box .

Thanks for tip.
 
Last edited:
Here is my 12 volt battery/6 volt starter OZ style resistor thanks to Lawrie's tip.

The shadow across is a bit offputting.

I used a single 1/8th dia arc welding rod, bolted between the 2 posts of a screw down battery cutoff.

It works great, I span motor over, it felt much slower and easier on starter, and screwed down cutoff and it sped up slightly, so it is doing its job.

So, normal operation is unscrewed and if I overheat the rod and need more power, simply screw it down temporarily.

I will experiment with 2 lengths of rod after tomorrow, as I had to get this going quick for its first club run tomorrow.

I did change the fused wire to direct to the battery post, after I fitted it and realized it was wrong.

modelA12battresistor.jpg
 
It would be helpful to obtain two voltage readings while the starter is running:

1) between the two battery terminals, ground (earth) and hot.

2) between the battery ground terminal and the power connection on the starter itself.
 
Pooch,thats a good idea with the bat cut out,,
I used a nylon strip to mount my resistor on.
Lawrie

5055029867_bd4e7a2efb_z.jpg
 
It would be helpful to obtain two voltage readings while the starter is running:

1) between the two battery terminals, ground (earth) and hot.

2) between the battery ground terminal and the power connection on the starter itself.

Update Peter.

Battery static after running 30 seconds, waited 30 seconds to stabilise voltage and let resistor cool ..12.75 V across batt posts.

Voltage after resistor with engine turning over is 7 V, after 2 seconds, dropped to 6.5, another 2 seconds to 6V. then rapidly down as resistor got red hot.

So, as far as I want it, it is working fine, starter is nice and slow as a 6 volter should be.

My engine starts on the first turn.

I changed the .125 arc rod to .090 thick.

The .125 was reading about 10 V and doing multiple starts. so I reckon it was too thick.
 
Back
Top