KZ550 - no spark!

I'm not getting any spark and I'm wondering how I can test the coil packs. I tried unscrewing one of the plugs and grounding it to the chassis, and tried the starter. Would turn over, but produce no spark. I checked the voltage on the 12v wires going to the coil packs. It actually only read 9v.

1. Is the 9v a problem, maybe not enough to power the coil packs? And if so where do I go from here.

2. How can I test the coil packs? With the plug out and grounded, I tried manually grounding the negative on the coil pack to the chassis and still got no spark, is this how to test it or is there a different way?

Thanks in advance.

Hey Dev,

I'm not KZ expert... only now working on my second ever KZ but in the spirit of helping out a nearby KZ rider here goes:

I just went through this same problem last night with my son's bike - a '72 honda 350cl - no spark at plug that was grounded to cylinder during engine starting.

What I did was to pull the points cover off and then check the point gaps.
One was barely able to make contact, while the other was fine.
So I adjusted the "loose" points so it could make contact first. Then used some emory cloth (or even some folded-over sandpaper of the 400+ grit range would do) and pushed/pulled it a few times between the closed point's contacts to buff-up the point's contact surfaces in case they were corroded (the bike has not been run since '92).
Then I had my son roll the engine over with the starter button while I watched to see the points arc'ing - they did after the contact buffing and resetting of gaps!

Finally, I connected a brand new spark plug to a plug wire and grounded it again to the cylinder head and again rolled the engine over (points cover was still off during this too). I got sparks on the points AND on the plug. Tried the other plug wire with another new plug and ditto - cha ching!

Now on his honda the plug wires are fused into the coil pack... On my most recently completed KZ440 the wires are twist-into the coil packs and on that bike I had to replace the plug wires. I used some spare plug wires I have for my Vdubs in the shop and it works great!

The coil's input wire should be getting 12v.
That 9v reading is low.
A 12v battery is considered discharged at 10.5vdc

You might have some corroded wire connections in the path from battery to switching to coil... A wee bit of inspection and perhaps cleaning of contacts along the path may help. Mebbe a battery charge too?

I dunno the specs exactly on a KZ coil yet (still waiting for any of my ordered manuals to arrive) but by way of example, the coil in my Vdubs has 12 volts on the positive input terminal and puts out 35,000 - 40,000 volts to produce those nice blue arcs across the plug gaps.

HTH... Hmmm... Hope you don't have electronic ignition... and if you do, then ah ... nevermind
:whistle:

What model and year 550?

TheDevilZX wrote:

I'm not getting any spark and I'm wondering how I can test the coil packs. I tried unscrewing one of the plugs and grounding it to the chassis, and tried the starter. Would turn over, but produce no spark. I checked the voltage on the 12v wires going to the coil packs. It actually only read 9v.

1. Is the 9v a problem, maybe not enough to power the coil packs? And if so where do I go from here.

Yes, that is a possible problem. I would find out where the voltage loss is, then clean the connection or switch. Or you can add a relay and some wiring to bypass the voltage loss.
If the battery is down to 9v when cranking, then it may be low or it could be the bike is turning over too slowly for the electronic ignition to generate a spark. (The electronic ignition's pickup pulse
is produced by a reluctor which requires a minimum RPM to generate enough signal.)

TheDevilZX wrote:

2. How can I test the coil packs? With the plug out and grounded, I tried manually grounding the negative on the coil pack to the chassis and still got no spark, is this how to test it or is there a different way?

I've found with the electronic ignition coils, it's difficult to generate a reliable spark by grounding and lifting the negative wire to the coil. Usually you will only get a spark at the negative wire. This dissipates the energy which would have gone to the spark plug. The key is to rub the wire quickly across a metal ground point so that the wire disconnects quickly.

Post edited by: loudhvx, at: 2007/11/17 01:03

1980 550LTD

Also to note this specific modification that may be in effect, I installed Dyna S DS2-2 Ignition.. No upgraded coils tho.

Ill start tracing to see if there are any bad wires etc. Any other advice?

With a Dyna S you should follow their trouble shooting procedures. It will be different than stock.

Ignore what I said about the speed of cranking. That will not affect a Dyna S. With the Dyna S, you can check for spark by slowly turning the carnk by hand. When the magnet lines up with the pickup, the spark should occur.

Check the voltage on the NEGATIVE side of the coils. If the voltage doesn't fluctuate from 0v to 12v as you turn the crank, the Dyna may have gone belly up. Your coils should be around 2.5 ohms. That is lower than the 3-ohms DYna recommends.