Battery charging system "off" on '77 KZ650--help?

Hi Everyone,

My bike's never acted up on me so I haven't had occasion to post on this forum, but a while ago, my battery began failing to recharge. I did all of the troubleshooting I could, bought a new battery, etc.--but long story short, I suspect there's something wrong with my charging system.

If I'm right--and I'm not very mechanically-skilled, so I'd need to take the bike to a shop--does anyone know what I'm looking at in terms of repairs, expense, etc? Or can you suggest "intelligent" questions I can ask about any solutions the mechanic proposes?

I'm also wondering, for future reference: for anyone who's got a bike like mine, do you have much difficulty finding parts (any parts)--or is the availability pretty good? I live in the SF Bay Area, if that helps.

Thanks a lot for any information or advice!

On mine, the regulator is part of the rectifier assembly. You have to replace the whole module. You could also have a bad stator not providing current to the unit.

Availability of parts for the old KZ's is pretty good. Ebay always has a bunch, and there are online dismantlers.

Actually the 77 is a one year charging system on the 650's with separate regulator and rectifier, I'd try the rectifer first.

Mark

Check the rectifier first, if thats not it it will be the regulator. The stators hardly ever go bad.

I've got a rectifier off a '77 KZ650 that tested good I could sell you cheap if you're interested. I also have a regulator for it I can dig up for you somewhere too, but I have no way to test it. First you need to test your charging system components. Here's a link to a free Haynes manual for your bike that tells you how to test the rectifier and the regulator: forums.kz650.info/index.php?topic=1833.0
Let me know if you want the parts.

welcome, first off in your sig, you say that it has a 78 motor, is it the 78 charging system also?

if you have a volt meter, you chould check to see if it is charging or not first, you can get a cheap one at just about any parts store that will do the job

as far as parts, I can recomend z1 , there is a link in the site, but it may be best to call them since you are looking ofr charging system parts

+1 on testing your voltage first and foremost. Get her running and put the positive lead from the voltmeter (or multimeter set to measure volts) on the positive battery terminal, put the ground lead on the frame or neg battery terminal. This will show you how many volts your bike is generating at idle, should be somewhere in the low 12's. Now rev the bike and see where the volts climb to, should be mid 14's. If these numbers are lower than it's likely the reg or rec (as mentioned before).

Also, as mentioned, the 77 is a one year only set up. The stator, regulator and rectifier are all different from later year bikes.

If you need to replace the reg and rec I highly recommend www.oregonmotorcycleparts.com . I've been running Tony's rec and reg for the last few years and went from undercharging to holding a solid 14.6 at idle all the way through the rpm range. His parts are cheap and he stands behind them too.

As far as where to take it to get fixed, good luck finding a mechanic willing to work on old bikes who actually knows what he's doing. There are very few of them around, and you almost have to go on local recommendations to find one. The good news is, you CAN do it yourself. With a shop manual and asking questions around here (and I might suggest www.kz650.info ) you can get through just about anything that bike will throw at you.

I have a '77 motor. The '78 motor you mentioned was in the sig of the first person who responded to my post. But thanks for your recommendation--I appreciate it.

check the water level in your battery over time if the charge rate is a bit high or you are using the bike in warm weather the battery's can go dry if that happens get some distilled water and refill the cells to the full line usally they will return to normal

Here's the single phase to three phase conversion on the Kz 650:

Ok, I had a problem with the battery discharging instead if charging after I fitted a Dyna s ignition, charging system was coping marginally with the power needed to run the extra relays, ECU, fuel pump and heated WBO2 setup that I use for the EFI that I have on my 650. If I used the headlights the voltage on the palm pilot display dropped to around 12 volts or less and at traffic lights it would drop to high 10 to low 11 volts.

After searching for info on this site and KZ650.info I found that the single phase stator that the 650b2 uses is the same dimentionally as the 3 phase stator used in later 650s and early 750's. I found that electrosports make a hi output stator ( approx 20%) more output than the late model 650 , early 750 models which had 21% more power than the B2 single phase unit. This works out to between 40 to 50% increase.
Lou and onkelb told me that I would need the 3 phase regulator/rectifier as well as the new stator.I got these parts from Pacific motorsports ebay shop and used the original 1phase rotor.

When the parts arrived I removed the 1 phase stator (2 wire) and fitted the 3 phase one ( 3 wire) with the original rubber grommet that seals the housing. There is a dimple where the 3rd wire goes, so I drilled the hole with a battery drill and a drill the same size as the stator wire.
I ran the 3 yellow stator wires to the one side of the 6 pin connector that I bought at the local car spares shop (which luckily enough turned out to be the same as the one on the electrosport regulator/rectifier), but I will have to cut the wires and put bullet connector in the wires when I remove the engine or the stator cover in the future.

The white wire is the output to the battery, I connected this one to the white and red one that was used with the original 1 phase reg and the same with the black wire that connects to ground. The brown wire is the Reg load wire (connects to the 12v switched wire that i traced back from the rear brake light positive wire)
and that was it.
Used the bike for about 300KM now and the charging is all good

Parts were:-
1 x Electrosport ESR370 Regulator/Rectifier $89.95 from Pacific motorsports
1 x Electrosport ESG010 Heavy duty 3 phase Stator $109.99 from Pacific Motorsports

stores.ebay.com/Pacific-Powersports-Accessories
Hope this info is useful for anyone else with a 650B2 that is converting from 1phase to 3 phase charging system. Special thanks to Lou (loudhvx) and Bo (onkelb)and incognito0160 as well as all the other guys who gave advise and ideas.

Taken from the www.kzrider.com website.