Here's the pertinent info:

94 FXRP with 72K. Daytona Twin Tec Ignition 1007 external. Power Arc Single fire coil.

I'm riding home today, about 20 miles on the slab. Air temperature was around 100. Suddenly I lose power and limp off an exit. I pull over and determine that the front cylinder isn't firing. Let it cool down about 10 minutes, and it starts and idles fine, but as soon as I put a load on it, the front cylinder drops again.

Trailer home, and when I get here, it starts and runs around the block just fine. Put a meter on the coil, and it reads 5.6 ohms on each of the two primary circuits (testing front and rear each to the center). I couldn't find specs on this particular coil, but I think it's supposed to be a max of 3 ohms.... right?

Since I'm only dropping one cylinder, I'm ruling out the pickup in the nosecone.... Seems if that were failing, it would quit altogether, correct? My plan is to pick up a coil, new wires, and plugs (just because). What do all you gurus think?

Thanks in advance. Heading to Sturgis next weekend, and having a broken bike there would suck pretty hard. I'd drink a lot more though.... ;-)

 

from what you describe it sounds like you have a bad coil.

 

+1 on the coil....Been there done that. It "could" still be the nosecone unit as I have had a Dyna S single fire unit chit itself in the heat.

Although from what you describe its most likely the coil.

 

Always try plugs first as they are cheap and Evos are fussy about plugs, even if they look OK they can give a range of symptoms from bad coil to bad pickup or module....having said that, it could quite easily be the coil with those symptoms.

 

Bah! Holding for parts til at least Tuesday.

Spanners, it could be a plug, but with the trip coming up, I think I'll throw a coil and wires at it too.

 

If you have scoped the coils as good , i would agree with Spanner.
Swap the plugs , check for bad plug wires .
Re; plug wire check ... ohm. them or spray some water on them in a dark area and look for arcing to ground.

 

Daytona coil, Accel wires and a set of NGK Iridiums installed. Seems to be cured. Now just check the fluids again and clean it up, and we're off to Sturgis!