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Discussion Starter · #1 ·
Hello all,
Looking for some advice. I just finished cleaining and rebuilding a used honda starter motor for the CX500/GL500 (and probably many other models). When I received it, it was obvious that the previous owner had taken it apart. I applied 12 volts to the post and grounded the motor body to negative on a charged (13.8V) lithium battery and got nothing..no sparks, no smoke, but also no running starter motor. So I elected to rebuild it complete with new electrical plate, brushes, fiber washers, seals etc. When testing the components for continuity prior to reassembly this is what I found:

  • the body with internal windings had no continuity between the positive lead and the metal body itself (y)
  • there is continuity from the body positive lead to all individual copper elements that make up the internal winding cicuit (y)
  • there is no continuity between the two brushes mounted on the electrical plate (y)

- On the armature/commutator there is continuity between both ends of the shaft, and from both shaft ends to the main armature part in the middle (shiny silver metal middle section). There is NO continuity between the armature shaft/ shiny metal middle section when tested to the copper commutator where the brushes ride on. I think this is the way it should be, but would like confirmation from you all if you know.

So far so good I thought. However when I assembled everyting together, The motor made no effort to run when 12 Volts was applied. Furthermore, there IS electrical continuity now between the HOT + post and the starter motor body, which to me seems like a dead short.

Your thought/comments would be much appreciated.

Cheers
JP
 

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It will appear as a short to earth via the starter motor power lead as it is very low resistance but it is perfectly normal - the earth circuit is via the starter motor body.
Are there any signs of sparks/a circuit during your attempts to run it?
Does the motor spin freely?

Have you tried it with a good battery - preferably a decent size car battery?

Has the +ve power post on the starter motor body been correctly assembled with the insulating spacer/washers etc?
(from your testing where you have no continuity here it looks like it has but i`d ask,anyway)

Does the +ve brush lead on your new brush plate have insulated leads?
If they do not it`s possible that when assembled the leas is touching the internal body of the end cap causing your short.
 

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Discussion Starter · #3 ·
Thank you for your response. Yes, the positive post has insulating fiber washers and a small rubber o ring beneath that. The positive brush wires have insulation, while the negative brush which grounds to the plate and then starter body, are just bare copper wire without insulation.
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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You might need to pull it apart again to recheck continuity on each component, then at each stage of reassembly.
 

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Discussion Starter · #5 ·
SOLVED UPDATE#### Jah Rider you win the prize! As it turns out, having some "bleed through" continuity between the body and the + post was not my issue. For the purposes of just bench testing the starter motor I stupidly used too small a gauge of wire. Once I tested using an appropriate size wire gauge, there were a few sparks as I added 12 volts to the + post, and then vroom the starter motor spun up with great gusto.

Jan thank you again for your remarks about battery strength which caused me not only to try a spare car battery but also propted the use of an appropriate size wire.

You really gotta love this forum, and all it does to help us in the CX500/GL500 community.

Cheers,
JP
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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I just checked resistance through a working, unrestored starter and read 1ohm.
P.s. It appears you resolved it while I was in the garage. 👍
 
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