Coil Testing

Hello all long time no talk!! Anyhow my old kz1000st has been in "timeout" since July!! I have been having electrical issues/ignition problems and kinda lost interest after it let me down and stranded on the side of the highway. Anyhow since it's winter here in good old Nova Scotia I am now going to fix it up over the winter.

I have always suspected the coils were weak. My plugs always fouled and the solder on terminals were soldered once too many times and I had to splice the ignition wires and I found one had a crack.

So I have a clymer manual but is as old as the bike and the setting on the multimeter don't jive with mine but heres what i got:

resitance from plug wire to plug wire is 14.50 when set at the 20000k for one coil that is cracked and 11.67 for the other.

resistance between the + and - of the coil is .002 for the cracked one and 003 for the other. I couldn't get ant other readings. Do these mean anything to anyone, any feedback? are the coils within range?

1979 kz100st or e1

I'd suggest getting a new set of ignition coils from z1 enterprises. Also replace the sparkplug caps I belive they seel them too. Coils test usually from 2.3-3 ohms new.

Where they are mounted is not very friendly to long term life especially if the engine is idled for long periods of time. All the heat is trapped under the gas tank baking the coils.

Going through the bike's electrical system cleaning every electrical connector and contact should improve the reliabilty. Check the handle bar switch pods for corrosion.

Another thing to consider is replacing the ignition switch for a new one as the original one is subjected to vibration and wear from years of use.

As MFolks suggests, I would go with a new set of coils. Plugs and wires/caps while your at it.

If anything is old enough to crack, it should have already been replaced, and ignition components and the lines that supply power/signal to them are critical.

Sometimes you really do just have to throw some money at her! :laugh:

Cheers, good luck.