That @#^%$@!!! KZ650!

Oh, I hate that bike!

It's sitting in a Taco Bueno parking lot, about 1/2 mile from my work, dead as a doornail once again! 2 years, and i've gotten to ride it less than a thousand miles!

Argghhhh!!!!!!!

(Details to follow when the rage subsides)

PS Taco Bueno sure is great, isn't it? That Chicken and potato Burrito is the nuts!

Glad you enjoyed lunch at least. Now let's here some details, I've had my 650 for 32 years maybe I can help.

Mark

Define doornail. There are many levels of dead and sometimes they just play dead to make you appreciate the good times.

It's a '79 KZ650 B3. Man, it's such a good looking bike. Reminds me of my ex-wife, though ... beautiful and sexy, but so, so much grief?

I bought the bike in July of '07, and the electrical problems started before I handed over the cash. The battery was bad, so it was kickstart-only. I wanted to be sure the starter worked, so the seller obligingly hooked the jumper cables up to his F-150 and she started right up. I didn't know you're not supposed to do that. On the way home, to work, and back home again, every light bulb on the bike blew out. The next day, we found it was charging at some outrageous rate, and the two-year nightmare of trying to get this thing right started.

Over that period, I replaced the stator (used) three time, the voltage regulator twice (used), the battery twice (new), the coils (new Dyna Green), a new Dyna S ignition, etc. This past winter, I walked away from it in disgust and bought another bike. Last month, I hooked up with a super meticulous retired railroad engineer who does amazing frame off restos-on bikes. We bought a new regulator from Z1 Enterprises and had Rick's rebuild the stator. The battery tested perfect on a hydrometer. I started riding it last week. Three days ago, the battery quit starting the bike, it became kickstart-only. Last night, it lost 500 rpm on the idle and the headlight went very dim at idle, but would brighten up when revved. Today, it lost another 200 rpm at idle just before it quit for good.

Clearly, it is not charging properly. If it was the battery, it would still make enough power to run, wouldn't it? Even with a bad battery, a properly charging bike wouldn't dim the headlight at idle, would it?

This war with this bike has absolutely been the most demoralizing experience of my life, and I was married! (longest three months of my life).

I can futz my way around most electrical systems with a reasonable degree of sucess. 1st start from the basics and 'assume' nothing. Double check all the easier componets 1st. Some charging systems have to have a minimum of 12.0 V to operate. If your battery is less than that, maybe charging it is a good idea before going any further.
After you have charged it and before you reinstall it, LOAD test it ! Some battery/s bench test just fine, but the real test is when the battery is required to produce amperage. Without load testing it you will never know the true condition of the battery. Warped, broken plates, or even worn out electrolite then become obvious.
I have seen old hard wiring be the cause of many, many charging as well as lighting problems. HARD wires do not conduct electricity very well at all. Hence causing even more problems. Such as blown fuses, relays, burnt up connectors and wires. Bad, missing or even under sized ground wires seem to be the problem a lot of cases. Check those very carefully for painted connections, corrosion, etc. at the mounting surfaces. If all that fails to find the problem, put the battery in, and start doing your tests from the armature/stator 1st, working your way back to the regulator, fuses next then ignition switch. Always test BOTH sides of any inline connections. I know electrical problems can seem very frustrating and confusing. Its what we don't know or we assume that gives us the most problem...LOL
One last thing you may want to consider.
When you purchase 'used' parts for anything this old your buying 25+ yr. old parts. They may be on their last leg when you purchase them.
BTW I have carbs rebuilt by the same folks @#^%$@!!!
I hate those guys....LOL
Good Luck !

It sounds like a bad regulator/rectifier to me. I would check everything edspring1 said too.

Mark

Would assure negative battery cable has good clean ground where it attaches to the engine (or frame).

Would charge battery overnight, then check charging system by measuring voltage across battery terminals. At idle rpm look for 12+ volts. At 3000~4000 rpm, look for 14+ volts.

Imo, it's okay to jump from a automobile battery so long as the automobile engine in NOT running.

Good Luck!

Thanks for the advice guys. The problem is, it's all such familiar ground. Mark, the regulator may very well be bad, but after going through four of them (the latest one brand new), I'd have to say if it is bad, it is a symptom, not a problem. There must be an underlying cause. Same story with the stator. This is #3, and again, it hasn't gone 300 miles since being rebuilt by Ricks.

And Ed, I understand what you're saying about used parts, but one of those stators and two of those regulators came off of bikes that were running, and charging. They all failed within a few hours of being put on this bike. Now, the same problem presents itself within a few operating hours of having a brand spanking new regulator and a brand spanking freshly rebuilt stator installed by an electrical engineer whose shop and work would just make you drool.

When he finished installing these new parts and replacing the harness ends with new, factory type ends, the bike was charging dead on the specs in the Clymer manual at both idle and at 4000 rpm.

Patton, I'm confident the grounds are good. At one point, after cleaning the factory grounds for the umpteenth time, JCCWall, who was working on the bike at the time, even added an extra ground to see if thatr would help. It didn't, and is no longer on the bike.

Ed, maybe the problem is in the 25 year old harness. Honest to God, if it's blown the regulator or stator again, I don't know what I'm going to do. I paid 500 bucks for this bike 2 years ago. I have over 5000 bucks in it so far, and all I want to do is get it running well enough so I can sell it to someone and still look at myself in the mirror the next day. I figure the best I cn hope for out of this bike is 2,500.00, and I am not about to put anymore regulators and stators on it just to have them eaten within 300 miles, as so many others have. Something is causing this bike to eat regulators, stators and batteries, and if I can't find out what very soon, and very inexpensively, the only thing I can see to do is part the bike out. I hate to do that to a bike that runs and has a title, but I just can't take any more of this grief. If you want a laugh, look at some of the history here.

kzrider.com/index.php?option=com_kunena&...ew&catid=4&id=159192

kzrider.com/index.php?option=com_kunena&...ew&catid=4&id=224336

kzrider.com/index.php?option=com_kunena&...ew&catid=4&id=236374

And that's just the charging issues. You don't want to see all the ones over the carbs. What a nightmare!

I've never been so totally demoralized over something in my life.

When I first got my bike I had some wiring issues. Turns out some of the wires near the neck were broken and only made contact when you weren't turning a certain way. Maybe you have some sort of wiring that is making contact and shorting out the charging system somehow?

I'm confused about the idle speed. You state that "it lost 500 rpm on the idle and the headlight went very dim at idle, but would brighten up when revved. Today, it lost another 200 rpm at idle just before it quit"

That's 700 rpm? KZ650's normally idle between 950-1050 rpm so if you lost 700 rpm it would naturally quit (they won't idle below 500 rpm).

Regarding "Even with a bad battery, a properly charging bike wouldn't dim the headlight at idle, would it?"

I've owned my '77 KZ650C1 since new. It has a different charging system than the newer models (thankfully) but whenever the battery needs to be replaced (every 3 or 4 years) the bike will warn me by quiting at idle or displaying very strange behavior of the idiot lights. So my experience has been "no" the charging system alone won't keep the bike running consistently at idle if the battery is shot. As far as the headlight dimming, that is a definite, the headlight will dim somewhat at idle even when the battery is good, but with a bad battery it will grow very dim at idle. Also, unless you have installed a new electronic flasher unit, the turn signals will blink slow or won't blink with a bad battery. Ed

Here is some good reading that goes in depth with therory of the charging system. It is from the GS Resources web site. The GS is so close to the KZ. The Suzuki engineers of that time used the KZ as a starting point and changed very few thing so they could call it thier own. Talk about plagiarism. Any ways read through all of the stator papers and something might jump out at you. I had a bike that would shock me every time I pulled in the clutch or front brake and couldnt find the problem, even though the coils are the only thing on the bike that would produce that much voltage. It would still trickle when the bike was not running with the key on, I was stumped. Electrical Gremlins can be very frustrating as you have experienced. Good Luck and read away.

www.thegsresources.com/garage/gs_statorfacts.htm

Not sure if you meant this in frustrated just but "On the way home, to work, and back home again, every light bulb on the bike blew out" would be a good sign of where your problem lies....

To blow open every bulb in the bike says you had extreme overkill in the charging circuit most probably originally due to faulty voltage regulator. These are +12Vdc bulbs on OEM configurations (Non LED) and probably take up to +14Vdc but since you blew out ALL, some serious voltage was applied.

Same time via Ohms LAW of Voltage, resistance & current.... the conductor size and voltage drops across the conductors are calculated accordingly.

Chances are when this originally occurred, some of the conductors where fried as well, thus melted conductor insulation thus shorted conductors...

Maybe I missed it, has a new wiring harness been installed as well as the stator/rectifier/regulator?

Just a thought,

OMR