Topic: Bench test a starter?

[cleveland]

How do I bench test a starter?

Thanks!

[troppo]

Whats your level of electrical smarts?
Assuming you know the basics, you need the following..
starter
bench
battery
light jumper leads (lighter than car jumper leads)

put battery and starter on bench
connect leads to battery
connect negative to starter body (or negative terminal on starter)
connect positive to starter terminal

starter will wind if OK
this is the basic test procedure for cars, same technique for starter solenoid, but i`m sure we`ll be informed if its different for these old bikes
Cheers
Troppo

[Raul CB750K1]

Get a loaded battery, negative lead to the starter body, hold the starter firmly, and connect the positive to the starter bolt terminal. There will be sparks and the starter will give you a considerable shake, but it will start spinning and that's it. The shake is due to the momentum; as the rotor tends to remain still, the body tends to turn on itself. If the motor is toasted, it will either don't turn or be a short circuit, so be ready to remove the positive lead if it doesn't start to turn after the first sparks....  

[cleveland]

Very cool, thanks guys!

[754]

The torque will be surprising   

[cleveland]

I picked up a CB200 and I the starter is not working.  So I figure if I bench test it, I will know if it is a wiring issue, or a starter issue. 

[TwoTired]

Be aware, hitting it with juice is just a rudimentary test, as there is no load on the motor.

Had one once that spun on the bench and wouldn't work in the bike.  The shaft bearings inside were worn and when under load, would allow the armature to contact the motor frame, shunting the power away from the armature and nearly negating any power output.  Without load, the armature spun centered in the frame.

Another had the commutator brush worn away.  The connecting wire allowed the motor to spin on the bench (brief test).  In the bike, the connecting wire melted in about to motor revolutions under load. A true smoke test, that one.

Now, I usually bench test spin an unknown starter motor, after I inspect the bearings, brushes and commutator.

Cheers,

[754]

If my merory is clicked on,


CB 200 mounts on the front, like CB 350/450

They have far more starter problems being exposed to the weather and all, needc much more attention..

[cleveland]

Good to know, thanks for the heads up. 

The actual problem is that the power will shut off when I hit the start button.  I am thinking there is a short in the wiring, but I though checking the starter would be a good starting point.  The strange thing is that the fuse does not blow.  The power shuts off the same on my 550 when I have blown a fuse.

[TwoTired]

The starter motor circuit is not fused.  They draw 100 amps or more during operation and would require a pretty big fuse.
The starter solenoid control circuit is fused, though.

The actual problem is that the power will shut off when I hit the start button.

Check the battery connections between the battery and starter.  If they are loose or corroded, they won't support the high currents of the starter motor, and break connection.

Cheers,

[cleveland]

You seem to be "Johnny on the spot" every time I have questions.  Thanks a million!

[City Boy]

Always remember when diagnosing lectric troubles;Order of probability is 1-connections,2-wires,3-components.This is especially true with Japanese products.

[Bodi]

That's odd.
When you push the start button and all power goes out, the power to the solenoid coil should go out, too and it should click off.. letting the power come back on. So the result should be a loud buzzing from the solenoid and very dim lights.
I've had car batteries that measure good but have a bad internal connection - they can supply a little juice but not a heavy load. I have never seen one that would light a headlight yet fail on starter load though: usually they will run a car radio and maybe the dome light but with headlights or ignition on it acts like someone disconnected the battery.
Does the power stay off (like a blown fuse) and, if so, what do you do to get it back on?
Does the bike power stay on with the starter disconnected (remove the starter motor wire from the solenoid without changing anything else) when you push the start button? The solenoid should click.
I would check the heavy ground wire from battery "-" to whatever large bolt it attaches to. And the heavy red wire from battery "+" to the solenoid post.

[dustyc]

When I got my 750, the starter didn't work.  When I pushed the button, the light would dim, so I reasoned the button was doing something.  I connected the solenoid terminals using a screwdriver across the terminals and the starter spun, so I reasoned the starter worked.  I replaced the solenoid with a spare(might have come from you Cleveland) and it worked fine.  Hope this helps.

[ev0lution7]

i was listening to 2 friends of mine talk about starters one day and here is what they said:

"Hey bill if i set my starter on my table and hook it up will it run?"

Bill replied: "No, starters dont have legs!"

i always laugh to myself when i hear someone trying to hook up a starter out of a car/ bike / lawnmower i just think of my 2 friends having a conversation about starter... just thought i would share that with you guys.