Scrambler Ailing Scrambler

I am having trouble with my 2006 Scrambler. The eng is stock with only bolt on goodies around the bike. She is not firing on one cylinder. The bike cranks easily, but that is about all. I have given her a thorough inspection, visually, and could not see anything obvious. I tried fresh plugs, but the old ones were almost new. That was not it.

She is getting fuel, and I did not see any airway restrictions, so that left the fire. I pulled both plugs and laid them against the eng to check for spark, and there it is. Good spark for one and nothing for the other.

I am looking at the coils now. I have a Triumph manual for her but it does not show any kind of way to check a coil to see if I am correct. Does anybody know of a way, with a multimeter. If not, I suppose that My next move will be to order a new one. While I'm asking for help, Is it a good idea to replace only the bad coil or do they both need to be replaced.

I haven't stripped the bike down to remove the coil yet, so this could be premature. Anyway, thanks to anybody willing to give their 2 cents.

 

Thanks for the great ideas. I'll try all tomorrow, as my time is spoken for the rest of the day. And yes they are stock coils. I have really been lucky to have ridden as long as I hav and never had an electrical issue. Well, just once, but still! Thanks again. I was on another website checking out new replacements, $150.00 apiece.