Cooter
Well-known member
I submit this problem to the Buell Brain Trust (BBT)TM for your consideration, plenty of smarter people on here than I am, and I've lost enough hair already:mad-new:
Bubbles '05 XB12-Scg, 10k-ish miles. All stock except K&N, Drummer, and matching IDS ECM. Very well maintained, never sits for more than a week or 2 at a time, and the last thing she put in was clutch plates and an oil change about 2 months ago. It's been running perfectly since she bought it, until now
90* clear day, 150 miles into a ride and over 40 miles from the last fill up, her bike lost spark to the front cylinder only. First intermittently but then completely in less than a couple miles It will still sometimes, but only very occaisionally fire on both cylinders, but mostly nothing.
I did all this under a shade tree in the dirt near Caliente, CA, so forgive the improper procedure:upset:
I pulled out the plug, grounded the electrode, and no spark at all while it runs on the rear cylinder and the rear cylinder runs dependably (got 50 miles at 60mph to a hotel on the rear only, yay Buell:eagerness
It has NGK DCPR8-EIX plugs that are new and very clean. I even swapped on another plug from my XB just in case. Still no spark in front. Her plug fires fine on my bike ('08-STT) and HOLY CRAP the DDFI-3 spark plug cleaning feature is a surprise when you turn the key on. I will NOT forget that anytime soon
Both plug wires ohm fine, I made a new 7mm plug wire for the front (Thank YOU Mr Rodriguez and your '85 Old Cutlass Supreme hot rod project), and even swapped the plug wires front to rear, No spark in front.
With a plume of a grass fire in the distance... I swapped coils from my running bike (same part #). No spark in front, and mine still runs great with her coil in it. Even though an ignition coil (step-up transformer) does not need any chassis ground to work perfectly, I grounded the mounting bolt anyway, no change.
I ohmed both the primary wires between the ECM and coil. The front one is the one with the "dyno loop". They have good continuity end to end, infinity to ground, and I wiggled the crap out of them while doing it. I even pulled the pins from the connector and completely bypassed the front primary wire with a new length of wire to be sure. No change.
Coil power wire is fine, and both cylinders would be affected anyway.
I used ECMDroid to fire the front and rear cylinder. Spark in rear, no spark on the front.
Thinking the driver in the ECM that fires the front plug was overloaded/bad, I rode 360 miles at 90MPH to pick up and replace the stock OE ECM for the bike. No change.
I eliminated the CPS as the cause because it has only one output (to the ECM) where the ECM then uses that signal to time and split the spark primary signal. So if there was a CPS issue, both cylinders would have to be affected.
I'm not one for replacing parts as a guess because thats lame, expensive, and time consuming:stupid: but thats what I'm down too. Since the bike is back home now, I think I have another (the 3rd) coil to swap in:mad-new: Whats Satans phone number again? I have something to sell him:concern:
TL;DR
No spark in front cylinder only, and I've tested or replaced everything except the fuel pump:black_eyed:
One free Buell drain plug O-ring to the first person to get it right!! You have to get it in person, but it does come with a cold beer and a long talk about motorcycles:love_heart:
Bubbles '05 XB12-Scg, 10k-ish miles. All stock except K&N, Drummer, and matching IDS ECM. Very well maintained, never sits for more than a week or 2 at a time, and the last thing she put in was clutch plates and an oil change about 2 months ago. It's been running perfectly since she bought it, until now
90* clear day, 150 miles into a ride and over 40 miles from the last fill up, her bike lost spark to the front cylinder only. First intermittently but then completely in less than a couple miles
It will still sometimes, but only very occaisionally fire on both cylinders, but mostly nothing.I did all this under a shade tree in the dirt near Caliente, CA, so forgive the improper procedure:upset:
I pulled out the plug, grounded the electrode, and no spark at all while it runs on the rear cylinder and the rear cylinder runs dependably (got 50 miles at 60mph to a hotel on the rear only, yay Buell:eagerness
It has NGK DCPR8-EIX plugs that are new and very clean. I even swapped on another plug from my XB just in case. Still no spark in front. Her plug fires fine on my bike ('08-STT) and HOLY CRAP the DDFI-3 spark plug cleaning feature is a surprise when you turn the key on. I will NOT forget that anytime soon
Both plug wires ohm fine, I made a new 7mm plug wire for the front (Thank YOU Mr Rodriguez and your '85 Old Cutlass Supreme hot rod project), and even swapped the plug wires front to rear, No spark in front.
With a plume of a grass fire in the distance... I swapped coils from my running bike (same part #). No spark in front, and mine still runs great with her coil in it. Even though an ignition coil (step-up transformer) does not need any chassis ground to work perfectly, I grounded the mounting bolt anyway, no change.
I ohmed both the primary wires between the ECM and coil. The front one is the one with the "dyno loop". They have good continuity end to end, infinity to ground, and I wiggled the crap out of them while doing it. I even pulled the pins from the connector and completely bypassed the front primary wire with a new length of wire to be sure. No change.
Coil power wire is fine, and both cylinders would be affected anyway.
I used ECMDroid to fire the front and rear cylinder. Spark in rear, no spark on the front.
Thinking the driver in the ECM that fires the front plug was overloaded/bad, I rode 360 miles at 90MPH to pick up and replace the stock OE ECM for the bike. No change.
I eliminated the CPS as the cause because it has only one output (to the ECM) where the ECM then uses that signal to time and split the spark primary signal. So if there was a CPS issue, both cylinders would have to be affected.
I'm not one for replacing parts as a guess because thats lame, expensive, and time consuming:stupid: but thats what I'm down too. Since the bike is back home now, I think I have another (the 3rd) coil to swap in:mad-new: Whats Satans phone number again? I have something to sell him:concern:
TL;DR
No spark in front cylinder only, and I've tested or replaced everything except the fuel pump:black_eyed:
One free Buell drain plug O-ring to the first person to get it right!! You have to get it in person, but it does come with a cold beer and a long talk about motorcycles:love_heart:
