Cleaning your starter motor

I've seen posts in the last year in which folks had starter problems and purchased new ones.  If you are prepared to replace the starter, then there's no harm in trying to clean the old first.  Mine acted up over the summer by turning only small amounts at a time before the engine would start, so I took a look.

Contrary to what the service manual says, the left engine cover need to be removed at all.  If the gears don't line up when putting the starter back in, don't force it, the gears probably aren't lined up.  Simply remove it from it's home, turn the motor a bit, and try again.  Mine went back in on the 3rd attempt.

Two long screws hold the starter together.  One was stuck so back that my impact wrench couldn't break it loose.  I cut it off with a hacksaw, removed the pieces, and replaced it with a new one.

Upon disassembly, I poured out what seemed like a cubic inch of coal dust and cleaned all surfaces with electrical contact cleaner.  My bike is still low mileage so I have plenty of "brush" left.  They don't look like they are difficult to replace when the time comes as long as I can find a set and can break the wire screws loose.  I'll cross that bridge when I come to it.

Some starter motors are very difficult to reassemble because of brushes that fall out of their slots, but not this one.  Simply carefully expand the brushes so that they slide over the winding.  Then consult the service manual to see how the end caps need to be aligned with the body.  Make sure that your screws are completely parallel to the body of the starter or you risk damaging the threads and it won't be properly tightened.

I've only started mine twice since cleaning it good, but it performs like new so far.

I've never had any joy when renovating the starter motor and I've rebuilt 3 of them.

I'm pleased you've had success but does it start reliably when the engine is hot?  This is where my rebuild let me down.  I suspect that the insulation on the outer coil windings is breaking down.

My bud Ray routinely refurbished fjr1300 starters. He'd put the guts on his lathe, take a bit of commutator down to ensure roundness, replace brushes, clean up internals. One thing Iearned from Ray was when repositioning the case, with case slightly loosened, and motor running, monitored by amp meter, rotate, move the housing slightly for minimum current draw.



 

One hundred seventy miles yesterday in 85 degree F heat running errands making multiple stops (towns here are far apart).  The starter only went, "Werpp..." once, otherwise worked flawless.

Ted wrote:

One hundred seventy miles yesterday in 85 degree F heat running errands making multiple stops (towns here are far apart).  The starter only went, "Werpp ..." once, otherwise worked flawless.

Is that a technical term? 

It's in the service manual under 'Troubleshooting'.