Hi, All. I’m having some extremely strange electrical issues. I keep getting stranded thirty miles from my house and I’m looking to go ahead and stop that. I’ll ride the bike for a good long while and then suddenly I’ll start to feel a loss in power until it just dies and won’t start (dead battery).

Bike is a 1999 CBR600 F4. New regulator/rectifier (from Ebay, so cheap) that was replaced due to the old one popping a capacitor right through the potting (and an extra I had not passing the diode test). As far as I know, original stator. New battery.

I’ve tested the current reg/rec and it passes the diode test. It does get very hot at operating temp, which is mildly concerning, let me know if this may need to be examined more in and of itself.

The stator…does weird things. None of the leads go to ground, resistance is close to the same between any two of them. When the bike is running, if I have the stator unplugged from the reg/rec, my AC voltages are close together between all phases and go up/down predictably with RPMs. When I plug the stator into the reg/rec, however, AC voltages on two of the three phases modulate properly, but the center (on the plug) phase actually goes down in voltage with RPMs. Normally I’d be quick to diagnose the issue as the stator, but when its unplugged it’s not the same story. Strange.

I probably shouldn’t leave out that the neutral indicator on the cluster stops working when the bike is up to operating temperature, and the clutch lever starter kill starts working. When the bike is cold, the indicator works, and the clutch switch does not. This is the case every time the bike runs. Very unusual issue, but may be helpful to ultimately tell if my issue is really fixed, without having to ride the bike out somewhere until it dies.

Any help is much appreciated. I’m pretty much scratching my head at this point, and tired of throwing parts at the bike. If anyone has more thorough tests I can perform, that would be excellent. Thanks!

 

You should have continuity between the stator terminals.
New R/R, new battery, and original stator. I'd replace the stator. Hopefully it didn't ruin the new R/R.

Are you charging connectors all good?

 

Crap. My mistake. There is continuity and resistance values are all close between terminals. Same recommendation? Hoping to have another way to test before dropping the cash. Thanks for the quick response!

 

Have you checked the charging voltage at the battery to verify that it's really not charging?

 

I haven't, how should I go about that?

 

Put your voltmeter on the battery an rev it to 5k rpms. It should read 13.5v to 14.5v.

 

Just tested, here are the results:

On cold start: 13.7V at idle, 14.8V at 5k RPMs
After warmup: 14.12V at idle, 14.17V at 5k RPMs

 

It's charging.

You have another issue.

 

Tested a bit more last night after I got home, and some interesting stuff showed up. I let the bike run and warm up even farther while I worked on some other stuff in the garage, and when I came back to it, voltage across battery terminals was like 11.8V, not increasing with throttle. Furthermore, continuity was not present across the stator leads.

I shut the bike off and disconnected the stator from the reg/rec, and there was some (very high resistance) continuity between the leads.

I think at this point I can probably call it the stator. Thanks so much for your help, by the way!