Starter issues

[chuck hahn]

Im not well versed on starter motor functions. Whats happening is it will spin like mad out of the bike. Installed it barely creates enough torque to move the crank. Im not sure what is the issue or for that matter how does the motor produce torque to spin the engine???

[Grimly]

You may find a bad connection inside the terminal on the casing, or perhaps one or more of the windings is defective, robbing it of rotational power.
Might be a new set of brushes is all it needs, though.
It's amazing how grunged up they get internally yet still work.

[chuck hahn]

brushes seemed to be real long with lots of spring pressure holding them to the armature. I blew all the dust out and greased the ends that go into the caps and nothing changed.

[Brendan W]

Check the voltage drops between the case and batt -ve and between motor supply post and batt +ve during cranking?

[chuck hahn]

Brendan... When i put the starter from my bike into his ike it cranked normally without fiddling with anything else. This, to me anyway, would indicate the other two starters were dragging azz.

[Brendan W]

Bearings ?
I've see one or two where the magnets are touching the rotor.

[chuck hahn]

Armature didn't feel sloppy in the end caps. I can revisit that before throwing them in the dumpster.

[Brendan W]

Might not be the bearings fault. Have seen magnets come adrift enough to rub the rotor.

[uk gs nut]

Polish the comutator and make sure none of the brass segments don't have very small burrs to track between each of its neighbour's

[Redman]

Sound like you have had the starter motor out, and apart.
Are Commutator bars (on the rotor, where brushes ride) dark colored? (upper right)
If so that is, brush material is worn into the copper. Clean it up with emmery cloth. (lower left)

[chuck hahn]

Yes i split the cases and blew all the carbon out with compressor, lubed the ends of the armature and spun it by hand to feel for smoothness. Then spun it off the truck battery while out of the bike. Reinstalled and no change in operation. It tries to form enough torque to crank the engine but just cant make it happen.

[Redman]

Yes i split the cases and blew all the carbon out with compressor, lubed the ends of the armature and spun it by hand to feel for smoothness. Then spun it off the truck battery while out of the bike. Reinstalled and no change in operation. It tries to form enough torque to crank the engine but just cant make it happen.

Yes. You said that all before.

Two of us have since mentioned/asked about the condition of the commutator bars . . . . . . . . .
Shiney copper? Darkened black?
Smooth? Groved? Wavey?
Good clean gaps between? Filled with brush materail? Copper worn over between?

.

[Cipher]

One assumes an alternate starter cranks the engine properly.?

[Gorminrider]

tests:
if holding the spinning starter feels like a big angry squirrel, it's probably ok. (Squirrels are strong.)

use that car battery to start the bike (disconnect bike battery) OK? you may need a new bike battery OR something is dragging in the engine see removal of spark plugs...

check the solenoid by
a) applying "+" to the small green/yellow wire after disconnect it at its join under the seat or wherever OR apply +to where it solders onto solenoid. This tests the solenoid itself and may indicate the button on the handlebar is the problem
b)by shorting it out with a screwdriver or heavy wire across the two LARGE Bolts . SPARKS! It's a WELDER! so no fuel around and make the test quick to avoid sparks and welding to the lugs

as mentioned, does a different starter work?
things that indicate: reduce compression by removing spark plugs Might serve to ensure starterclutch ok
check starter clutch under flywheel?

armature burned out? gets HOT! winding resistances? broken winding? without a good ohmmeter you couldn't test for much more than continuity of each winding by testing opposite contacts as you slowly turn it , but you MIGHT see some clue as to continuity or a big diff in one portion of the turn

[chuck hahn]

i cleaned up the contact area for tge brushes with 2000 AND we took the bike battery out of the loop and i put bolts into the bike cables for jumper cables to bite on. straight from truck battery and no change.