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Hey Guys, I have a 79 KZ400 that has been stripped and made into a bobber. This is my problem and I'm sure someone has asked this before, but I couldn't find the same for my bike. I was ridding and my headlight went out and the engine started to cut in and out. I pulled over and the bike died, I turned my headlight off and the engine would idle, I decided to continue home but the engine would sputter all the way home. Once i got home I found that my battery was dead, no problem changed battery and found my systems not charging! My bike is only kick start now, checked for continuity on the stator wires (2 yellow) and have continuity between them, check each stator wire for direct ground to the engine and that checked good with no short. disconnected the 2 ea yellow wires and at idle checked for power and found none, increased rpm's to 4000 with same result no power. checked the resistance on the stator wires and had .4 . I'm thinking my stator is bad but I think all my checks are good except I have no power on them. Any help would be greatly appreciated. The cow pie!

I rechecked the yellow wires coming from the stator and I have 74vac @ 4000 rpm. I checked the rectifier and only get reading in one direction. Does anyone have a good regulator/rectifier for a 79 kz400?

I don't know if "only get reading in one direction" confirms a bad rectifier as I'm no electrical smart guy, but have you made sure the connections going to and from the rectifier/regulator are very clean and snug? And that the wire from the regulator that charges the battery is good?

OKC_Kent wrote:

I don't know if "only get reading in one direction" confirms a bad rectifier as I'm no electrical smart guy,

That's the way it should read. The rectifier "bridge" in the assembly has two silicon diodes and two SCR (silicon controlled rectifiers). The two diodes will read a diode drop when the meter is connected across them in proper polarity (open in the other direction), but the SCR's will read open regardless because their gate's are not enabled.

I followed some the trouble shooting steps from the manual, and it said I should have a reading both ways, I don't remember the numbers off the top of my head. I also found my connector to the rectifier was melted. I tried the to get the some reading off the wires before the connector and it was the same result. I checked all connections and that's when I found the melted connector for one of the wires coming from the rectifier. Everything else checks good, except this!

Cow Pie wrote:

I followed some the trouble shooting steps from the manual, and it said I should have a reading both ways, I don't remember the numbers off the top of my head. I also found my connector to the rectifier was melted. I tried the to get the some reading off the wires before the connector and it was the same result. I checked all connections and that's when I found the melted connector for one of the wires coming from the rectifier. Everything else checks good, except this!

Melted wires would tend to suggest the thing they were connected to (the rectifier assembly) got extremely hot. I would suspect that it might not survive.

I ended up switching out most of my electrical system. Wire bundle and all. Old wiring.........

A problem with one part could overload other parts, leading to harmful voltages, wrecking more parts and burning wires etc.

One possibility is that the energy that burned the rectifier wire (the rec.'s power perhaps) might have channeled elsewhere as well.

This is frustrating in that you fix a part that tests well and should work, but doesn't. It may be due to another problem that caused the fixed part to fail in the first place.

I discovered that in areas where there is little heat dispersion (i.e. in a wire bundle where the other wires and black tape contain heat) that the excessive power may have burned insulation of one specific wire, and in doing so burned adjacent wire's insulation as well.

I don't mean to add more to your plate, but I would search the whole wiring system to find shorts, damaged insulation, brittle/broken/burned wire, dirty contacts or worn connectors before I started purchasing new components.(battery rectifier....)

Check continuities!!! Perhaps there is a wire shorting to ground or another wire that should not be doing so.

I would isolate the charging system. Disable all accessories and see if the problem persists, then add accessories back one by one...

Just some thoughts..

Thanks for the info guys! I have looked at every wire in the system, my bike doesn't have very many wires to it anymore since the bike was converted into a bobber. It has been stripped of everything except what is needed to run, head light brake light and tail light. But as long as I have the system torn apart I'm doing a complete rewire and I'm hooking the elec. starter back up only when I don't feel like kick starting it. I've got some photo's on this site under cow pie, I didn't build this bike but I ended up being the lucky owner, it's a thrill to ride. I'll keep you posted in the future on the out come. But by all means keep the sugestions coming!!

FYI... I changed the rect/reg. and replaced my battery and my electrical system is working good now. I'm getting a good charge to my battery. Thanks for all the info and imputs!!!

Coe Pie

Gert some good electrical contact cleaner and every few months spritz the connections. Do not use WD-40 as over time it becomes a non conductive coating/insulating substance. A good brand to get is De-oxit made by Caig Labs in San Diego Ca. www.de-oxit.com