What is that noise?

[motoproponent]

Howdy folks. Having a hard time trouble shooting this one, I thought I would look to some fellow banditos for advice.

Every now and again when I start the ole 2001 B12 it makes this horrible noise that sounds like a starter clutch slipping on my old 1979 KZ 750. It's a single ping/clack/pop kind of noise. The noise only occurs right after the engine lights off but it looses all electricity for, like, a millisecond.

I know it lost power because the tach and speedo needles do their boot up sweep and the clock is reset to 1:00.

I've checked the battery and wires. Everything is solid. And it only happens once every 10 or 15 starts. It does it regardless of engine temp, ambient temp, whether or not it's the first start of the day or starting after the 3rd fill up of a long day in the saddle.

I don't even know where to begin trouble shooting?

[mosquito]

Just guessing...  Is it your daily ride? (Which would mean more starts than a weekend bike.)  Know if your starter has brushes?  Assuming yes and yes, I'm wondering if the starter brushes are well worn and the jolt of the engine starting and starter disengaging is causing an arc inside the starter somehow.

For troubleshooting, I dunno since it's not easily reproducible.  I'd prolly pull the starter and look for signs of arcing.  Maybe check out the starter relay too, but I'd expect any evidence to be inside it where you can't see it.

[motoproponent]

Hmmm I'll check that out.

I'm actually away from my beloved bandit at the moment, but when I get back home i have a few projects lined up.

I'll report back if I figure anything out.

Any more ideas?

[Red01]

I was thinking the starter clutch's retaining bolt is loose at first, since this is something that has caused grief for a few folks, especailly on '01's.  Seems some factory assembler wasn't applying torque/loctite to it properly for a while that year. I'd have thought it would have reared it's ugly head before now though. OTOH, that probably wouldn't cause the electrical problems you describe.  Still, might be worth checking anyway, just in case it's a contributing factor - and especially since you said it sounds a lot like a slipping starter clutch.

[stetracer]

From what your saying about the electrics resetting I would check and clean all your grounds

[motoproponent]

Yeah, Checking he battery connections, fuses, and ground was the first thing I did.

[H2RICK]

Mosquito +1.

You're probably getting some kind of short in the starter and that causes a HUGE voltage drop.
Electronic stuff (like your ECM components) have what's called  "must-operate voltage" limits. Too high...something fries. Too low and the ECM goes to sleep....just like turning the key off AND just as abrupt. As soon as the voltage comes back up to the lower limit of the MOV (after you take your finger off the starter button), the ECM comes back to life. The ECM (and thus your clocks) then goes through the whole startup cycle just like when you first turn the key on.

My .02 worth....

[motoproponent]

Mosquito +1.

You're probably getting some kind of short in the starter and that causes a HUGE voltage drop.
Electronic stuff (like your ECM components) have what's called  "must-operate voltage" limits. Too high...something fries. Too low and the ECM goes to sleep....just like turning the key off AND just as abrupt. As soon as the voltage comes back up to the lower limit of the MOV (after you take your finger off the starter button), the ECM comes back to life. The ECM (and thus your clocks) then goes through the whole startup cycle just like when you first turn the key on.

My .02 worth....

That sounds like it's right on the money. If I pull the starter motor is there something I can look for? Is there a bench test or diagnostic check I can do?