How to test a Starter

[gaillarry]

I suspect the starter on my 85 GS550 has gone south. I can turn the gear on the end of the starter in both directions with pliers. I though the gear only moved one direction?

Whats the best way to bench test the starter? I hooked 12v + to the starter nut and the ground to one of the starter housing bolts, but no spin!!

[DanTheMan]

I suspect the starter on my 85 GS550 has gone south. I can turn the gear on the end of the starter in both directions with pliers. I though the gear only moved one direction?

Whats the best way to bench test the starter? I hooked 12v + to the starter nut and the ground to one of the starter housing bolts, but no spin!!

If it won't do anything after hooking to 12v power and ground, you've got a bad starter. That's the way I test them, it should spin....

[txironhead]

Agreed that the starter is toast, but I'm curious about the gear turning. The starter turns both ways, but the starter clutch does not.

You can either rebuild the starter if it's salvageable or replace it if it's not and/or you don't want to rebuild it. Rebuild parts and rebuilt starters are available at good prices here: www.stockers.com.

[SqDancerLynn1]

starter clutch is meant to only turn one direction

[SPARKSS]

The starter itself will turn both directions freely......just a DC motor. The clutch is external on yours as I recall.

Because you can't power it up with your correct connection (assumed your power supply or battery was adequate), then, given that it's a permanent magnet, wound rotor motor, the MOST LIKELY thing wrong is that the brushes are worn out. Try powering the starter as you did.....and gently tapping the motor case which may cause it to motor even briefly......good results here will tell you that it's basically ok except for the brushes. You could also disassemble it to easily verify this......nothing ventured nothing gained at this point. If you can't source the brushes, try your local automotive starter/alternator rebuilder and you might be surprised at what they may be able to come up with.....even if you have to carefully file them to fit....and/or rework the lead ends to suit.