Solenoid issues

[Mustek]

Hi team,

I have a 95 DR650.

Its blown about 4 starter solenoids now.

I had it into Coleman’s but they said they thought it was dodgy connections and an aftermarket solenoid. They replaced the connections and attached a Suzuki branded solenoid which was supposed to be higher rated than the job required.

The starter solenoid has now blown the 4th unit.

I therefore have the following questions:

1) Does anyone have any idea what could be causing this? (Thanks for the help in the other thread)
2) Is there any reason why I shouldn’t keep jumping the poles of the solenoid to start the bike? Pretty over paying out when the issue probably won’t get found anyway.
Cheers,

[Paul in NZ]

If it uses some kind of frame earth return I would suggest a separate earth wire to ground it properly..

[Daffyd]

Possibly a short circuit in the starter. If it's drawing more current to feed a short, then it can certainly overload and blow.

[Mustek]

Possibly a short circuit in the starter. If it's drawing more current to feed a short, then it can certainly overload and blow.

Cheers for the reply. How would I diagnose this???

Is there any reason why I shouldn't continue to put connect the 2 terminals manually to start the bike (apart from being a giant pain in the ass)

[pete376403]

Easiest diagnostic would be by substitution, ie another starter motor. You could put an ammeter across the motor and see what sort of current it is pulling, but for that to be meaningful you would need to know what the specified current draw is.

shorting the terminals to start it is all the solenoid does, just more conveniently. (thought - when you do short across the terminals, does it spin up normally or seem a bit sluggish?)

Have you ever pulled the starter motor apart to check the bearings. It's not unknown that they fill with crud and spooge.
http://justdr650.com/starter-motor.php

[jellywrestler]

how long is the bike taking to start? there's two options, excessive current being drawn, or normal current being used for longer than designed for

[Paul in NZ]

The thing is - how is it failing? If it was excess current the contacts inside the solenoid would fail or burn out but it might still operate. If its not actually operating then its something on the operational side?

[OddDuck]

A bit of a long shot, but if the solenoids are repeatedly burning out due to excess current draw, have you tried pulling the starter motor and checking the brushes / commutator assembly?

It's possible to get a short via carbon dust buildup, either across the brush mounting plate, or across the commutator itself if there's carbon buildup in the grooves. Cleaning will need some electrical contact cleaner, cotton buds and so on. Also as Pete said gunk in the bearings won't help - every bit of resistance that the motor is working against will increase its current draw.

The second test that comes to mind is a bit easier: get a multimeter (on the DC Volts setting) onto the starter solenoid's coil terminals and check just what voltage is applied across the coil. Is it the full 12V or is there a loss through the wiring harness? If there's only just enough to get the plunger to make contact then you could be getting a lot of arcing, hence rapid destruction of solenoids.

[Daffyd]

Cheers for the reply. How would I diagnose this???

Is there any reason why I shouldn't continue to put connect the 2 terminals manually to start the bike (apart from being a giant pain in the ass)

Just follow the others' advice.