Main Motorcycle: 2008 Bonneville Black
Join Date: Jul 2010
Location: Vicksburg, MI
Igniter, pickup coil or spark plug coil?
My 08 Bonneville is starting to develop an occasional miss. It manifests itself usually while cruising along at highway speed. It misfires (I don't know if on just one or both cylinders . . . I suppose if it was both it'd be technically two misses, but I digress) for just that moment and then keeps on as if nothing is wrong. One time it missed about 3 times in a row - maybe a second apart each time.
Knowing that there is an issue with the seat pressing on the igniter I took the seat off and checked the connections, they seem tight - when it did the multiple misses I stood on the pegs and it still did it, so I don't think it's actually the seat pressure. Anyway, the problem persisted.
Next, I again removed the seat and tried what one of my mechanic friends called a wiggle test. I wiggled the wires and the igniter while it was running, trying to see if it would induce the problem, but it didn't. I put the seat back on and the problem persisted.
Finally, tonight, I removed the seat, unhooked the igniter harness, smeared lithium grease onto the connections and replaced it all. I also put lithium grease on all four connections of the spark plug coil, and in the spark plug boots, ensuring that all of these connections were properly seated.
I took the bike for a test ride and sure enough, the intermittent miss at around 70 - 80 mph.
I'm now convinced that it's either a bad igniter, a bad coil, or a bad pickup coil. Does anyone out there have an educated guess which it most likely is?
The mechanic at the local shop said that he thought it was the igniter - he described my symptoms and asked if that was what was happening and I told him yes, and he said it was most likely that. I hate hearing that as it's so expensive for the OEM part.
If it is the igniter I know everyone is full of opinions about which one is the best, but I would be interested to know the prevailing wisdom.
"The possession of power inevitably spoils the free use of reason." Immanuel Kant
That explains why the sportbikers are driving like lunatics . . .