2003 teakettle 750 spark only on two cylinders

[Upshotknothole]

Trying to finish up the slabbie with a teapot 750 engine and we had it running great on the bench, finished up some other parts of the bike and now only getting spark to one coil. Swap the leads and the spark switches. Checked continuity from the ecu to the coils and both leads are good, as are the orange/white power lines. Any way to check the ecu before ordering up another? Cheers

Edited March 3, 2021 by Captain Chaos

[Captain Chaos]

1 hour ago, Upshotknothole said:

katana 750

[Upshotknothole]

34 minutes ago, Captain Chaos said:

Tea kettle 750 donor engine. 

[Upshotknothole]

Ok, this is driving us crazy. Slabbie 750 with an 03 teakettle 750 engine and harness. It’ll get derestricted later. It was running before, now we only get spark from one coil. Continuity tests good for the wires, swapped in a new ecu tonight and still the same thing. Multiple coils, and the side with the white single wire works fine, the side with the black/yellow signal wire has no spark. 
 

Sorry that it’s a teakettle and nothing cool, but we’re trying to finish this to get my friend off his old shitty Yamaha, so it’s for a good cause. 

[Upshotknothole]

Well fuck, looks like it’s something in the wiring to the acewell gauge we used. Unplug it and it fires up just fine.