Spark

[angus]

Turned bike over for first time in about 14 years,turns over ok (engine not seized) but no spark.I've new coils in from ebay says for kz 400,kz550 ect,and seller said they'd work,there is power to the kill switch side of loom but I've to bump the solonid to get it to crank over also power to the orange/white wires to the coils (but no spark) I'm not great with a multimeter but have 1 any ideas??.P.S it's the 80 550L canada/usa model

 

[Nessism]

I'd check voltage at the coils with the ignition on. You should see near full battery voltage. If not, you have a supply issue. The coils rarely fail.

 

[angus]

Checked voltage to coils orange/white wire to red on multimeter and black lead to ground ignition on over 12 volts is the reading

 

[Nessism]

Okay. I missed the part in your original post where you mention having power to the coils.

Have you checked spark on both coils? 1-4 & 2-3? Reason for mentioning this is if you had a coil failure on say 1-4, 2-3 would still spark. If you have no spark at all I doubt it's the coils because coil failures are rare and to have both go out at the same time is even more rare. I'd suspect an ignitor failure if there is no spark whatsoever. Sometimes when the R/R fails, or the ground corrodes, the voltage in the system spikes and that can take out the ignitor.

 

[angus]

Cheers ed only checked 1&4 will check 2&3 later I'll try post a link to the coils I bought to see if you think there alright.

 

[angus]

Here is link to coils I bought

http://www.ebay.co.uk/itm/Motorcycl...-21121-1035-/323049506243?hash=item4b374045c3

 

[Steve]

Before you go much further, check the resistance of the primary side. It should be 3-5 Ω.

I recently went through this, found I had improper coils on the bike.

.

 

[angus]

Checked 3&2 and had spark then tried 1&4 again after tightening coil cables and have spark now.

 

[Nessism]

Like Steve mentions, you might want to check coil resistance. The 1974 KZ400 had points which commonly use coils with more resistance than is typical for a bike like yours using a transistorized ignition. The Suzuki specs should be in your service manual and you can measure the coils directly.

 

[angus]

All plugs have blue spark now so thinking coils are ok

 

[Steve]

All plugs have blue spark now so thinking coils are ok

I had WONDERFUL spark on all plugs and thought the coils were OK, too. Fried the ignitor. One of the rarer ignitors.

Over the years, that had happened more than once. I finally did some troubleshooting and found that the Accel coils (right up there with Dyna as "desireable upgrades") only showed 1.0Ω on my meter. My leads alone are 0.3Ω, so the coils themselves are 0.7Ω. Yep, Accel does offer 0.7Ω coils, and I believe that Dyna does, too, but they at least color-code their different coils, so when we say "get the green coils", there is no mistaking what you want.

Suzuki specified coils of 3-5Ω for the bikes with electronic ignition. As Ed mentions, the Kawasaki that those coils were meant for probably had points, so the coils might have had a slightly higher resistance, maybe in the 4-6Ω range.

It's quick, it's cheap, it's easy. Do yourself a favor and follow the advice that Nessism has in his signature:

To measure is to know.

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