Electric Start Blues

concours · Apr 22, 2023

Uncle Frank said:
Well I've tried connecting the battery straight to the starter motor and it still won't turn the engine over. Took the primary cover off to remove the starter and saw that the shouldered nut on the anti backfire device has broken - guess I'll have to see to that before I proceed any further.

Great job remote troubleshooting.

For those following along, the tests were to rule out some potential problems, and also confirm viability of some systems/components.
A clamp type ammeter would have told the story in 10 seconds, but, I assumed the OP didn't have one, based on the questions asked.
These tests allowed us to arrive at the answer, using only a common voltmeter. A test that could be done on the side of the road, or at least in the Pub parking lot.

Everyone should have this in the bag: Amazon product ASIN B07PHDJRP3

Uncle Frank · Apr 30, 2023

The issue has been resolved. With everything pointing to a fault in the starter I disassembled it and found one of the brushes was hanging up and not making contact with the commutator effectively turning a four pole motor into a two pole motor. Dave Comeau helped out - I advise anyone working on one of these to contact him because reassembly is very tricky until you have the knack. My thanks to all who responded to my post especially Dave Comeau who has been in contact from the word go.

concours · May 2, 2023

Uncle Frank said:
The issue has been resolved. With everything pointing to a fault in the starter I disassembled it and found one of the brushes was hanging up and not making contact with the commutator effectively turning a four pole motor into a two pole motor. Dave Comeau helped out - I advise anyone working on one of these to contact him because reassembly is very tricky until you have the knack. My thanks to all who responded to my post especially Dave Comeau who has been in contact from the word go.

Glad you got to the bottom of it.

Anton vesely · Jun 15, 2023

concours said:
Great job remote troubleshooting.

For those following along, the tests were to rule out some potential problems, and also confirm viability of some systems/components.
A clamp type ammeter would have told the story in 10 seconds, but, I assumed the OP didn't have one, based on the questions asked.
These tests allowed us to arrive at the answer, using only a common voltmeter. A test that could be done on the side of the road, or at least in the Pub parking lot.

View attachment 105961

Everyone should have this in the bag: Amazon product ASIN B07PHDJRP3

What amps readings are we looking for here ?

Torontonian · Jun 15, 2023

L.A.B. said:
An easy test to identify a faulty solenoid is to bridge the two terminal studs with a screwdriver blade or similar but be prepared for a few sparks.

Yes this is what I do for an older questionable solenoid switch . A solenoid's purpose is to send it a weak signal from the party button to electromagnetically bring the 2 BIG contacts together to suck up BIG power now to the starter motor . Big sparks will fly but that's O.K.

concours · Jun 15, 2023

Anton vesely said:
What amps readings are we looking for here ?

Edited. My SWAG was way low.

The maker of the starter is here, could give you EXACT numbers.

bluto · Jun 21, 2023

concours said:
Great job remote troubleshooting.

For those following along, the tests were to rule out some potential problems, and also confirm viability of some systems/components.
A clamp type ammeter would have told the story in 10 seconds, but, I assumed the OP didn't have one, based on the questions asked.
These tests allowed us to arrive at the answer, using only a common voltmeter. A test that could be done on the side of the road, or at least in the Pub parking lot.

View attachment 105961

Everyone should have this in the bag: Amazon product ASIN B07PHDJRP3

That "amp clamp" in the photo is AC only like most and not useful for vehicle work, models that do AC and DC are harder to find and more expensive...but very handy.

DennisMo · Jun 21, 2023

I guess about 200 Amps.
Dennis

concours · Jun 21, 2023

bluto said:
That "amp clamp" in the photo is AC only like most and not useful for vehicle work, models that do AC and DC are harder to find and more expensive...but very handy.

Used to be true...

Amazon product ASIN B0BVZJ7NCZ

Dan1950 · Jun 21, 2023

Have you tried the kick starter? Always works for me and I'm getting close to 73 yo.

Electric Start Blues

concours

Uncle Frank

concours

Anton vesely

Torontonian

concours

bluto

DennisMo

concours

Dan1950

1974 MK II Roadster

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