There is a diode between the AC pin and the kill switch on this CDI.

When measuring the AC to ground pins it appears as though it is open circuit one polarity and has a diode and resistor the other.

You are correct about the chaffed wires, they did short on the thing rubbing against them, which was a metal pod air filter that was connected via a rubber boot, therefore insulating the pod from earth.

I was taken back when I saw the 20amp fuse as the wire is only about 1.5mm2, so I'm lucky I didn't burn it to the ground.

All my tests show that the bike is still functioning the same as before with no spark again so I get another CDI and put a 1 amp fuse in as you suggest and see how I go.

Thanks again.

 

Why not buy 2 CDIs this time. If everything is good you have a spare, if not you don't have to wait for another one to arrive. My 5 pin CDI only cost about 4 or 5 U.S. dollars. Having a spare can be justified.

 

Funny you should say that, I have 2 in the post as of yesterday. Hopefully one will end up a spare and not a replacement for another dead one.

 

You are going to let us know if that fixes,(mends), it, aren't you?

You bloody well better!!!

 

FIXED, finally. So it turns out I now have a spare CDI and a quad that is putting smiles on the kids faces. So it must have been the bare wires shorting on the metal pod air cleaner.

Moral of this lllllllloooonnnggggg! story if you are fitting something new to a bike make sure that it is not able to rub against wiring as when the wires finally rub through to bare wire you are sure to have problems.

I'd like to point out it was not 'I', how put the new air cleaner on, I'm an electrician so wiring is of a very big concern to me.

Thanks again to Lynn and everyone else who contributed, my kids can't thank you enough.

 

I am glad the nightmare is over and that it was something simple.