Hi,

I recently rebuilt my bike as a streetfighter and in order to paint everything I tore everything apart besides the motor.
Prior to doing this, the bike ran fine on all 4 cylinders. The bike has been apart for about 1.5 years. It is finally back together,
and I have gotten it to run several times on 2 cylinders about 3 weeks ago. Ever since rebuild, I havent been able to get all 4.
It would start up fine, but infrared heat gun showed only 2 cylinders firing which were 2 and 3. I've been trying to test everything
and make sure all wires had good connection. Yesterday when I attempted to confirm that it was just a coil, I could only get spark out
of cyl. 3. So now it was only firing on 1 cylinder causing big backfires but the engine never ran. I kept checking, moving, switching
wires on the coils and now none of them fire. Eveything looked like it was connected and there is continuity. I made sure nothing was
left loose.

Does this sound like my ECU? I dont under stand why it would go from being fine @ 4 to 2 this year to 1 to 0 this month. I have it
jumped by a car battery so it has a steady 12v. Could it be ECU/CDI, R/R, Ignition pulse generator?



I've tested:
Both coils resistance per service manual => good
ECU harness per service manual (Power, coil power, ground) => good
I've switch coil wires around
Coil wires => Black w/White gives constant 12v power when kill switch is set to on. The yellow/blue gives off nothing even when cranking. A voltage spike is seen when i stop cranking. Is not shorted to ground.

What do you think is causing this?


Please help, I NEED to get this running ASAP. THANKS!!!

 

50 views and no thoughts? lol anyone??? ECU, wiring? Ign pulse generator?

 

i hope someone answers cuz mines doin the exact same thing. i can get a big backfire while spraying start fluid but thats it

 

FYI an ecu off ebay and a new set of plugs fixed my problem. not sure which it was but im guessing it was the ecu because my problem was intermittant.

 

i was going to ask what your plugs looked like when you pulled them, they sounded like they might have been oil fouled after the rebuild