Recently, my '08 Nightster started to take longer to start, and then it stalled a few times while going down the rode. It turns over so I think the starter is fine. I pulled my spark plugs and they were very much in need of changing, so I changed to new SE spark plugs and plug wires. However, the problem is still there. I'm not a certified mechanic, but I've got a manual and am comfortable doing whatever needs to be done. I need a little help with what all to look at to diagnose the issue.

I'm thinking maybe coil, and I read something about maybe the voltage regulator? What should I check, and how do I check it? Any help at all is appreciated.

 

Fixed. Plug wire was loose on the coil.

 

Not sure how/why it would shut down the bike altogether. Fire/run on 1 cylinder yes.
Unless both wires were so loose they made intermittent connections I don't know why the engine would shut off with a loose wire??
Bob

 

I have a similar problem, I was told the ECU may be going...going... gone.