weak ignition 440

was running the bike on the stand trying to tune carbs (with no luck) and all of a sudden it quit running and wouldnt even try to start.

My first thought was foul plugs so i repaced those. they had a pretty weak spark when pulled out of the cylinder. still no fire.

used a spark tester with plugs installed and had no spark..

very confused it seemed to quit all at once.

went through every connector with cleaner and sand paper. and the same with the points.

After testing the coil, it was within the specs supplied in the manuel. I know its getting fuel and air so that is not the problem.

Fully charged battery? Good electrical battery connections?(no corrosion,loose cables?).

Checked primary side(small wires) of the coil? it should be the same as battery voltage. To check it, remove the tank, using a multimeter set on VDC (Volts D.C.)range of 20, put the RED probe of the multimeter on the RED wire of the ignition coil, and the BLACK probe of the meter on a good ground or the battery Negative(-) terminal.

Turn the ignition switch on,run/stop switch to "ON" and read the voltage.If no voltage start checking backwards(the run/stop switch,the start switch, and electrical connections in the headlight housing.

Also check the glass tubed fuses, they can fail and still look good. Take them out of the clips one at a time checking for intact fuse element inside the tube, and for tight metal end caps.

These older bikes use the fuse designation of AGX. Do not try to put a AGC fuse as it may not fit. AGX fuses can be bought at auto parts stores. You'll probably need some 10 and 20 amp fuses.

now i havent check for loose cables around the battery yet. Now, if the ignition coil was to go bad would it just completely quit all at once or would it just get weak? the battery is fully charged though. In the morning I'll check out your idea.

Igntion coils can fail both ways, slow or all at once.What year is the bike? Probably orginal ignition coil?

If you have voltage to the coil,look at your igniton points, sometime vibration causes them to drift open or shut. They make and break the voltage going to the coil, creating the spark.

ive ordered new points and i have an extra condenser, if all else fails tomorrow morning i will go ahead and switch them both out. I believe its a 81 kz440 A? this is a bobber project that ive built from several different bikes and many parts from Ebay.

also is there an aftermarket ignition system that will fit on this bike? ive heard of some coil mods? im not very experienced with the ignition system so im in the dark here.