New KZ400, no spark

Howdy folks!

My pops just gave me a 76' KZ400!

Can't wait to get it lookin new, but I gotta get it running first! The tag on the license plate says 2000, so it's been sitting for 6 years.

My first attempts to get it started have been futel.

Bought a battery and hooked it up. Nothing. No headlight, no ignition lights, nothing. Traced the problem to the connector just before the ignition switch in the headlight housing. The white wire had a break. Fixed that, and everything powered up.

Now here's my delemma. No spark.

Replaced the coil, still no spark. Check the yellow/red wire, and it's got 12 volts. Hooked a check light up to the blue wire, and it flashes when the engine is turning (electric starter is AWESOME!).

Any idea why there's no spark? My dad had this problem getting it running last summer, so he ordered a used coil off eBay (that supposedly works).

Is it possible both coils are bad, or should I be checking something else?

I wanna get this beast on the road! Any help is appreciated!

If you dont have a service manual, I would suggest getting one (Haynes, Clymer, etc)There are probably places on the internet where people have put them up to share with others.
I would check the electrical connections first, then check for electrical current at the points (after you set the points). If you have juice at the points then I would follow the electricity to the coils to see if it is completing the connection.
A service manual really helps out when working on these older bikes. Most of the manual have the procedures to check the parts and some even have a troubleshooting chapter.
Sorry I couldnt be more specific. Congrats on your "new" bike!
Fish

wreckedmyteg wrote:

...Now here's my delemma. No spark...

I know this may sound like a reeeeeaaly obvious question, but can I ask exactly what you did to determine that there was no spark? I mean with a multimeter at the caps, removed plugs, etc.

Yes, it's possible though unlikely that two coils could be bad. However, a little more likely since you are uncertain of the origin of the replacements...

If you have a points ignition, the problem can be in the connections, as has been pointed out, or the points themselves, the condensor or the coils. Since you have power at the coils, you can visually see if the points are snapping when the engine turns over. If they are, and you have checked all connections from the points to the coils, the problem will be with your coil OR the condensors. The coil can be checked by measuring the primary and secondary impedence which checks the primary and secondary windings for shorts. This method is about 75 percent reliable for pinpointing shorts as some shorts can be intermittent. To check, you will need a multimeter. Check the primary impedence by first disconnecting your battery and placing the probes on the lugs on the coil where the power wire (yellow/red) and signal wire are attached to the coil. Put the meter on OHMs scale in the lowest setting. You should have nominally 3.8 Ohms impedence. If you put the meter in OHMs scale on 20K, and meaure the contacts where the plug wires seat, you should have about 15K Ohms resistance. This measures the resistance of the primary and secondary windings respectively. If either doesn't measure as noted, you may have a bad coil. If they check out, then you need to replace your condensor as I know of no good way to trouble shoot a condensor.

I know this may sound like a reeeeeaaly obvious question, but can I ask exactly what you did to determine that there was no spark? I mean with a multimeter at the caps, removed plugs, etc.

We checked for spark by taking a plug out, and grounding it against the case.

Since you have power at the coils, you can visually see if the points are snapping when the engine turns over.

I'm not real sure what you mean by this. I assume the points closing and thats why the trouble light flashes? The points opening and closing?

I'll probably just go buy a condenser since I think they're pretty cheap and it'll eliminate one more potential problem from the equation.

Here's how I think the coil works, correct me if I'm wrong...

The yellow/red +12 constant powers the coil. The blue coming out of the case near the condenser and spinning thingy that opens and closes (that's the points, correct?) triggers the coil and tells it to fire (when it closes and sends +12 to the coil). Is this correct?

What does the condenser do exactly?

I must admit that I'm pretty ignorant as to what points, condensers, & coils actually do, but I do know you can get points & condensers for $11.28 from Z1 . For me, that's cheap enough to just swap it out to be sure it's not the problem.

HTH,
-Kit

wreckedmyteg wrote:

...Here's how I think the coil works, correct me if I'm wrong...

The yellow/red +12 constant powers the coil. The blue coming out of the case near the condenser and spinning thingy that opens and closes (that's the points, correct?) triggers the coil and tells it to fire (when it closes and sends +12 to the coil). Is this correct?...

Yep. Kinda. All but this: "when it closes and sends +12 to the coil". You have it backwards, but it is not functually important here.

You say you put the timing light trigger on the blue wire and you have blinkiy-blinky. If you have the plugs in place, and you put the trigger on the spark plug wire (either of them) do you get blinky-blinky?

I don't have a timing light, just a 12v bulb with a wire soldered to it.

I don't think I want to stick the lead in the spark plug wire, cause I'm sure if the coil did send a spark it'd surely fry the bulb.

So when the point breaks the circuit, that's when the coil fires. Got it.

Does anybody know of a similar coil I could use as a replacement? I was told it just had to be a dual output 4 ohm coil.

wreckedmyteg wrote:

I don't have a timing light, just a 12v bulb with a wire soldered to it.

I don't think I want to stick the lead in the spark plug wire, cause I'm sure if the coil did send a spark it'd surely fry the bulb.

So when the point breaks the circuit, that's when the coil fires. Got it.

Does anybody know of a similar coil I could use as a replacement? I was told it just had to be a dual output 4 ohm coil.

I'm just gonna keep answering your questions until somebody tells me I'm wrong...

Ok, I thought you were testing with a timing light. You need a timing light anyway, so get one! Then try it on the spark plug wires. I was just suggesting you trace the failure from the coil, since you're sure you've got happiness *to* the coil. No, don't zap your little light!

Of course the wires themselves, or the caps, might be bad. You could just replace them, and somebody else has a thread going on right now about that....

If I understand it correctly, during the part of the crank cycle when the points are open (the gap), they are allowing the coil to charge. When they close, they cause the coil to fire. Actually, some really great descriptions of the process have been posted here before, perhaps in the archive. So if I'm wrong, it's easy enough to find out.

As for the coil, dual output is correct. I just installed a Dyna Dual Output 3.0 Ohm Coil on my 750 twin...

Update - I went to the local kawi dealer and both my coils tested good. The guy gave himself a nice shock, too.

He sold me 2 new screw on plug caps. If that doesn't solve my problem, what should I check next?

It was the spark plug caps on mine, the coil was good, but the caps were bad.

Good luck with that.

Update 4-20-06

Got the new caps installed on the plug wires and reinstalled the coil. Still no spark.

Maybe this will help...The one side of the coil has +12 constant (yellow/red) and when I hook my test light up to it, it's extremely bright.

When I hook the test light up to the other lead coming out of the coil (blue) that runs down to the points, the light glows but very dimly.

Is the blue lead coming out of the coil supposed to be a strong 12V? Would that be an indicator of a bad coil?

The coil did spark when he had the tester hookup up to it, but it didn't look very strong.

It's getting warm and I wanna get this bugger on the road!