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Odd spark problem


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Evening all, 

I’m having a bit of headache with my recently turbo’d 7/12 project. 
Got the tank back on her this morning, excited and fired her up, went round the block no problem. Happy days. 

Then I tried to start it again and nothing, checked the spark plugs which are new and no spark...

but it did spark if I held the plug about 2mm off the block, if it touched it’d not spark, take the contact away slightly and it’d arc to the block and spark O.o


luckily I’ve got a bit of a collection here so I’ve been trying a few bits.

ive swapped the coils first, no change.

swapped the plugs, no change. 

swapped the pulse generator, no change. 

so thought I wander if there is a positive current running through the frame stopping the spark ( I know I should have been a sparky!) 

so it seems there is 0.01 volts through the frame, only when the ignition is on. 
is this the problem? Am I looking for a wire?


I ive tried the searches but what the hell do you search with this??

Cheers y’all 

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If the other electrics work  that are negatively linked to the engine/frame, then all should be good. I've had a couple of problems in the past that were caused by the low tension wires at the coil flag terminals fracturing - sometimes the spark was good and other times I had no spark when the wire moved, the plastic sheathing hid the break in the copper wires underneath - it might not be this, but worth a check. The wire on the flag terminals that attaches to the coils get twisted a lot when putting them on and off, causing fatigue/fracture. I checked for continuity by disconnecting the ignitor connector, linking each end with the multi tester and wiggling the wire - continuity kept disappearing - the break was just before the crimp. Hope you find the fault.

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