How To Destroy A Starter Motor ?

Magwych

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Leave it running whilst you drive for about 20 miles ....

Now I have enough evidence I can back trace to my recent breakdown.

The bike is a 2008 MU GSA. The first symptom I noticed was an occasional drop in power and slight increase in vibration. This came and went for a while as I steamed up the M20 into London.

Once into the 'burbs I could hear a squealing sound that seemed to come from the front (right?) of the bike, which coincided with the dip in power, and the lights went out ( LAMPF error).

By this stage I was well into the Blackwall Tunnel Southern approach scrum nd thinking I really needed to do something about this. Some time.

Then the symptoms worsened, rapidly. Far more mechanical like noises from the engine, which then cut out a few seconds after these noises started. To add to the fun of being between lanes 2 and 3 on the North Greenwich Flyover, plumes of acrid smoke billowing out from under the tank and around the starter motor, ahh such joy. At least it was the downhill section so I could coast around the traffic and stop on the road side.

The boke was recovered to a dealership, who diagnosed the starter motor as having failed. Guess that will be the source of all the smoke then ...

New motor fitted, and all seeemed well, for 32 miles. The squealing noises resurfaced, and the drop in power. This time I heard it as soon as it happened, so I stopped straight away. When I turned the ingition back on the stater was running constantly.

Having spent a bit of time re-assembling 2 and 2, I cam to the consuion that the original starter was not the culprit, but the victim of something else. The only 2 components left are the switch button and relay.
I stripped out the switchgear and replaced the micro-switch. Then the hint was on for the starter relay. Disconnecting the relay feed wire into the starter I could hear the relay clicking whenever I pressed the starter button. After a long game of click and chase I finally found it hidden away under the BMS K unit - of what fun that was...

Whilst extractng the relay socket I found the break in the wire I have tried to show in the photo. The wire to the switch waskinind and spliyt, it was just touching against the voltage regulator at the back of the alternator. whenever it got damp, it provided enough of a path to earth to operate the starter solenoid.

It has been damp for a while now.

New section of wire added and it all works a dream - just need some rain for the final confirmation.
 

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Can't understand why dealer didn't check wiring the most obvious cause for such an event,Iv had cars with bad connections & many bikes with rotten wires,I'd guess the computer said it was just the motor so they don't bother :rolleyes:
 
Thanks for the heads up with a solution.

Just when you think you've seen all the faults, another new one pops up.

Glad you didn't end up with a bike on fire beneath you.
 
Ideal, cheers for the link. Will be checking this out on mine, not looking forward to the task going by what you say Martin...

Why? All i do with mine is ride and service it, i don't go looking for problems that may not happen.Now on 50k
 
Why? All i do with mine is ride and service it, i don't go looking for problems that may not happen.Now on 50k

I think his reason for checking is because he already has a problem with the starter circuit and wants to get to the bottom of it before (any more) damage is caused.
 
I'm with Roy on this. I could stick mu head in the sand and hope but stuff like this isnt hard to check for. If its only sticking some insulating tape over the wiring to stop it chafing it's worth doing. Other stuff like final drives (potentially) exploding - I'll deal with that when it needs a new wheel bearing. I'm def not going out looking for that sort of problem.
 
Yep like the guys are saying, im not activly out hunting for faults however given i have a problem i want to de-risk by checking out what another member has found to be a problem. I have a new switch fitted but i dont belive it will be the full harness thats been fitted, so i am deffinetly checking this out.
 


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