1986 vf 500 ignition coil problem

the ignition coils on my vf 500 fire like its running when i turn on the key switch. I thought it was the ignition module and replaced it but that did not work. Then i plugged in different coils. Still they fired when the key was in the on position. I admit that i left it outside under a tarp all winter. Has anyone seen something like that. Or does anyone have a wiring diagram.

 

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Does it fire when you crank on engine?

 

the problem is that the plugs are firing as soo as the ignition switch is turned even when its suposed to and not it was running great last fall till i foolishly left it out
i noticed a buzzing while i was pulling the carbs so i checked the plugs and they were firing like crazy so i bought a set of cdis on ebay since mine had the wires resoldered that didnt do anything i plan to buy a manul to get the specs to test the electrical componants. i posted to see if anyone had heard of that type of issue i havent

 

Hi chdarl,

I have never seen this happen... except when you use a screw-driver to jump out the starter relay to manually start the bike and troubleshoot the starting circuits. Perhaps more investigation into your start sequence is in order.

it may be something simple like moisture build up or ants or something similar has bridged a contact to be normally closed, when it should be normally closed... (I.e. you could repeat this problem by holding your finger thumb on the start switch when you key up the bike)

check out your starting circuit for corrosion or debris.

let us know what you find
Ghost

 

ghost

I do think ghost is on it. I am a little more than rusty on 500 but I think pick up coil plug would be a place to look for a poor connection/ corrosion problem. Not sure but I dont think cdi is looking at anything else so if cdi is new I would think cdi is get signal to fire from coil.?:thumbsup:

 

here's the wiring you need.

 

I really appreciate your replies!
I found out that the battery was bad and i had the charger clamped to the motorcycle. I dont know what the problem was but it seems like without the buffering of the battery there was too much voltage. I tried a different battery and the ignition seems fine.

 

I'm glad you said it "seems like it..." cause thats just not how it works.

My question is, what made the battery go bad in the first place? Was it simply just not properly maintained, and the water level went too low, or do you have a charging short somewhere thats over-charging your battery.

My advice is to determine what went wrong, else you will be buying a third battery shortly.

 

no the battery was no good it was old i threw it on to start the bike with a charger/starter i even tried it without the battery. the generator and regulator are charging in spec. ive started and run older bikes without batteries by jumping them with the same machine. The electrical looks fine there was a bad plug wire i replaced that and the spark is nice now.