I own a 2005 Detroit Chopper Aggressor softail w/a 96 C.I. S&S motor. My problem is when at idle only one cylinder fires. I changed the plugs and it worked for about 15 days and samo samo. What could be the possible causes?

 

fuel pak problem????????????.

 

maybe the parade mode (eitms) is kicking in too early?

 

Is it an EVO type engine with the ignition in the nose cone? If so the ignition module may be failing because it is in a very hot environment.

 

Change those plug wires.

Sounds like a small fracture / break and at low speed the pulse is slow enough to not make it past the break / fracture in the wire.

When you swapped out the plugs you repositioned the break and it made contact for a while.

I don't believe any EVO had the "one cylinder stops firing" feature like when the new bikes overheat at stops.

And most EVOs ignition module is on the frame (all factory systems are). Only aftermarket units were designed to mount in the nosecone, and some of them fail due to the high heat in that area.

 

try a different set of plug wires ....from a buddies bike ....bad wire will run you crazzzzy !!