TOPIC:

I have recently purchased a stock 1978 KZ650. After troubleshooting getting no gas to the carbs (previous owner had the bowls upside down after rebuild) I had the engine running rough but at least she was running. Later on in the day, I was showing my neighbor my new purchase. While trying to start, the battery went dead and my neighbor brought over a rolling charging system and tried to start her… like a jump from a car. She started no problems. I then removed the battery and charged it over night. Now, I am getting no fire to the plugs. I have power at the points and power to the coils...fuses good. Also, I purchased 2 used coils from a local motorcycle salvage yard and swapped out...still no fire on any plugs.

Is something fried?

Thanks in advance for your help.

Welcome to the site.

How have you determined that there is no power to the plugs? Did you try cleaning them or replacing them with new?

The prior owner obviously did not have it running as he/she had the floats in incorrectly. This means that it sat for quite some time. This can cause problems with fuel contamination and such. Possibly even foul a spark plug?

Could your points be fouled? Have you cleaned them or replaced them? If they are dirty enough, the bike will never sense them electrically as closed. You can check continuity with an ohm-meter.

You have not mentioned how much the bike has been ridden either. When your neighbor jump started it and it started no problem, was it just started, or was it ridden and running well? Was it still running rough, as it was earlier in the day?

Unfortunately, my 650 is a year older and has a different electrical system. I have also replaced the points and condenser out for an electronic ignition. Sorry I can be no expert here. I may only lob guesses.

Well I would say it was in the wiring. Maybe you knocked a plug out putting the tank back on OR could it be as simple as the kill switch? Some of the older reg/rec's don't like over amping them either. I hate jumping a bike.

Welcome to KZr Realnoisy.

Lets start at the beginning so we don't miss anything.

Was the battery in the bike the one it came with, or did you buy a new one?

If it was the battery the bike came with:

Did you verify it's condition and charge it first?
And even if it's an older battery and took a charge, it doesn't mean it will hold that charge - batteries lose their capacity to hold a charge over time/because the cells have become corroded or damaged.
If it was low on acid, did you fill it to the correct level using distilled water (tap water has lime and other nasties in it that can corrode the cells and prevent the battery from charging/holding a charge) and then charge it?
Was it charged using a charger on a low amperage (preferably 1/2 amp, but no more than 2 amp) setting?
Higher charging amps (upwards of 15 amps, as can be the case with chargers designed for automotive use) can literally boil a battery dry, or in a lesser case, damage the cells.

If it was a new battery:

Was it filled using the acid provided and fully charged (see charging amps recommended above) before being used?
Are the battery cables and all other connections corrosion-free, undamaged and tightened securely?

I'm curious, what amperage setting was used on the "rolling charging system" you used to start the bike with?
If it was a high setting like stated above, you may well have toasted your battery (and possibly the regulator/rectifier).

My suggestion would be to remove the battery and take it to an auto parts store (Auto Zone, Pep Boys, etc.) near you and have them "load test" it (most places do it for free).
Load testing puts the battery under a high amp draw, as would be encountered when you push the starter button.
The amount of time the battery is able to hold that amperage draw without dropping significantly will determine the batteries condition.

Once the battery has been deemed useable and/or replaced with a new battery, then move on to checking all of the bikes wiring for signs of damage (if a wire appears pinched but is unbroken, that doesn't necessarily mean the wires inside the insulation aren't broken), and check all connections for damage, corrosion, and that they are connected snugly.

There are quite a few electrical gurus here on KZr (Loudhvx is one of them) that are WAY more knowledgable than me and will hopefully chime in and correct anything that I've said that may be wrong, and will gladly offer more info on things to check for that I may have left out.

Good luck!

Thank you so much for taking the time to help me with this issue. I am not a complete idiot until it comes to electrical issues.

Here are the answers to the questions you have asked:

How have you determined that there is no power to the plugs? I cleaned plugs and held against ground looking for spark. I had great spark at plug prior to jump starting the day before yesterday. I will purchase new plugs today...it always good to have some extra ones anyhow.

Could your points be fouled? The points are new look clean and there is power at points.

You have not mentioned how much the bike has been ridden either. It hasn't been ridden in years. The carbs were rebuilt and never had gas in them prior to my ownership.

Okay, about the battery. I had the old battery on the bike at the time of the jump start while my brand new battery was being charged. We jumped the bike let her run, shut her down. I then removed the old battery and went to bed. The next morning, I put the new battery in it and no fire at plugs. Now, I tried to charge the old battery today and she is dead...totally gone! So it appears, the amperage on the charger was way too high and cooked the battery.

I have checked all the connectors and they appear clean and well connected.

If the kill switch is on "RUN" and there is power to the coils, would that rule out issue with "Kill Switch"?

Could it be the regulator/rectifier? Dumb question but what role does it play with ignition?

Again, thank you very much!

With ignition on, battery voltage is supplied to a terminal on the coil. The wire from the other terminal grounds via the closed points.

When the points open, the coil ground is redirected via the plugwires and through the plugs where it jumps to ground by sparking across the tip.

As power is reportedly already reaching coils and points, opening of points should redirect coil ground to plugs via good connections between coil>plugwire, plugwire>plugcap, plugcap>plug. All presupposing good coils, good plugwires, good plugcaps, good plugs, and clean properly gapped points.

Coil test. With ignition off, ohm reading across coil terminals (primary winding) should be 3-4 ohms (am guessing, so please check factory spec). Next, check ohm reading between plug wire ends attached to the same coil (secondary winding), which should be high, say 18K or more. No reading between plug wire ends indicates a break inside the wire, or a defective coil, or faulty connection.

The alternator generates AC. The rectifier converts the AC to DC. The regulator keeps the DC voltage in proper range (approx 14 volts). Thinking neither is a prime suspect in this case where battery voltage is reaching the coils.

Good luck with diagnosis and repair!

Issue resolved.

I had an extra set of condensers so replaced and replaced my plugs. Now this may not be a good way to test your coils but I guess it’s a good poor man’s way. I took off the plug boot on 4. There are 3 wires coming from the harness to the points a blue, green and black. I turned on ignition and took the green wire and grounded it to the block while watching to see if plug wire 4 had spark. Tada..it had spark. I tested the same way on 2 and 3 coil using black wire and had no spark. I tested another coil I purchased from a salvage yard and it had spark. Replaced bad coil, set gap on points and plugs and Varoom! I had to adjust the jets a little and now she purrs like a kitten. Drove her around the block a few times as well.

I want to thank all of you for helping me out. I have learned a lot from the information you have posted. I hope someday I’ll be able to help out newbie like me. Thank you, Thank you, Thank you!!!!!

Thanks for the report.
Glad to hear you're back up and running.

Well done, I think you are not a complete idiot with the electrical issues either!!

Correct me here, but isn't it true that if you place a lead acid battery on asphalt it will drain the current over time. I seem to remember my shop teacher telling us that way back.

That's actually an urban myth now. That was with the old "tar" batteries. New batteries now are not affected at all by what they sit on. With the insulated qualities of the plastic casing it does not matter.

Patton wrote:

With ignition on, battery voltage is supplied to a terminal on the coil. The wire from the other terminal grounds via the closed points.

When the points open, the coil ground is redirected via the plugwires and through the plugs where it jumps to ground by sparking across the tip.

First part is correct.

Second part isn't

When the points open the magnetic field generated by the primary circuit collapses, generating a electric field in the secondary, which travels out one plug wire, across the head, jumps the gap in the second plug, and travels back up the other plug wire to the other end of the secondary coil. No ground needed, the circuit is from one plug wire terminal to the other plug wire terminal on the coil, the coil does not have a ground on the secondary side, and the points/igniter provides the ground for the primary side.
It's called a "wasted spark" ignition because one spark occurs on the exhaust stroke, hence it's "wasted".

That's the simple description of how it operates