07 Classic: Bike quit running, lost spark on two cylinders

[Rumbleboomer]

Riding my 07 classic the other day an (idling along in second gear) all the sudden she quits running. After being towed home I removed the plugs which look ok but found I'm only getting spark to the
front cylinder. I'm thinking it didn't lose two coils at once so maybe an ICU issue? Where to test from
here? any ideas would be much appreciated, thanks in advance!

 

[scot in exile]

The real easy way would be if some member close by with the same ecu came over and switched them out, only takes about 6.75sec, I know the #1 coil is a pain in the arse to reach but swap them over and see if the spark follows.

 

[scot in exile]

You have checked for loose connections, corrosion etc etc??????

 

[Bob R]

I would start simple, check all connections, reseat the plugs on the ECU, then as @scot in exile suggested, start swapping coils.

bob

 

[Son_Of_Dog]

Here's some images that may help.

Wire Diagram for Classic:

Wire Diagram Key for Classic:

 

[Kevin frazier]

After you get it sorted give a fix update for us before you go tooling on and forget us waiting for what it was

 

[Rumbleboomer]

Thank for the come back guys, I am working on it today, will check all connections,
I'm hoping it's something simple, maybe a ground, having the plugs out I can easily spin the motor to see if I have the spark back, thanks for the input.

 

[TURBO200R4]

check for 12 volts on all three coils
if u take a 12 volt tester and hook it to positive then put the probe end on each of the terminals that the ecu grounds and crank it over the test light will blink if the ecu is doing its job.

 

[phar2slo]

Unless you have had the update kit done on your 07 I would say your leads have just given up.

Buy new coil leads for all 3 coils.

Also check spade terminals on coils as they work loose. Might need cleaning and a recrimping. I know about this first hand when over 400kms from home. If I rode at the speed limit ran fine otherwise not.

Could have fixed on the side of the road but waited until I was in the garage at home.

That's my 2cents worth.

 

[Rumbleboomer]

Ok, so I've been looking and testing all the connections, haven't yet removed any
coils an now I have spark to all cylinders but the spark looks weak.
So looking for a ground issue, thank you Son of dog for the wiring diagram.