Bonneville America Forums Forums Technical Forums General Tech Engine died on the way to work

So I'm on my way to work this morning, doing a steady 75mph and suddenly lost all engine power. Not electric, headlight stayed on. Twisting throttle did absolutely nothing. Had about a half tank of fuel and there was no warning sputter like usual, but just in case, I flipped to reserve, waited a couple seconds and gave a throttle twist. This time, it gave a massive backfire and I had full power. About a quarter mile later, same thing, only it stayed off longer. Fortunately, I was only a couple miles from work when it started acting up so every time I lost power, I pulled the clutch in and coasted and tried to dodge cars to make it over to the right lane and get off. Same thing kept happening intermittently, for random intervals. Seemed like it cut out when I was doing speed limit or above, and would backfire mightily and start running again when I slowed to 40ish. Exited freeway and my last couple blocks to work it only stalled briefly a couple times, seemed like when I was accelerating. At the parking lot, it was idling okay. No time to mess with anything, I had to get clocked in.
So I did a quick check on the forum and I'm suspecting either the ignition control unit (CDI?) or a pickup coil, from the little bit I've read.
It's not fuel; not behaving like fuel, plus the backfire when power comes back. It's not a spark plug since it's not only one side.
I'm going to go check all my connections on lunch break when I have a few minutes. Any other suggestions in the meantime?
07 America, 35,000 miles, electrics all factory original other than battery and plugs.
Thank you

Sounds like pick up coil. Get's hot shuts down, cools off and fires back up.
CDI would normally just start running erratically, one cylinder, popping farting etc. Run fine for a period, Then nothing, no fire.

Most likely what Mike said.

Or maybe, just maybe your tank vent hose is pinched off. Same symptoms occurred to me with the first modern Triumph I owned, including the backfires. Before I quit riding, I'll probably lose a pick up coil, hopefully not 4 states from home.

OR... it could be that my cotton-pickin' negative battery terminal screw was backed out and hanging on by about 10 degrees worth of the very last thread. My new theory is that that tenuous connection allowed enough amperage to keep the light on but not near enough to consistently deliver a spark. Tightened it up, checked my other connections, started and idled fine. Just to be sure, I checked the resistance on the pick up coil and got 600 ohms. I guess I'll figure out on the way home if the battery terminal was the sole cause.
Anyway, thanks for the input. I at least got a good education on my ignition system today.

haha, been there and done that. Here's the good part, you'll never let that happen again.

Do yourself a favor...
Chase all your wires from the battery, clean the connections, put no-ox on them and tighten them up err... down. lefty loosey, righty tighty unless it's a left hand thread.

https://shop.ptsupply.com/images/items/r3266l1/spec-sheet.pdf

Yeah that terminal has come loose on me a couple times over the years, usually when it's that loose it just doesn't start though. I just had the battery out a couple weeks ago, and I know I gave some good German torque, weird that it came loose that quick. I Locktited it this time though.

Good idea on the No-Ox - while I'm at work I'll see if the aircraft guys have some on hand to borrow.