I put a twin cam in my 1990 fxrs. used an 04 sportster wiring harness, o4 flt screamin eagle ignition module , custom chrome #605050 coil. The motor is a 2000 screamin eagle with 45 hrs mikuni. Bike will fire run for a second and die, Will not fire again until I quit cranking the starter, then will do the same. Tssm has been bypassed. Seems to be firing on rear cylinder even though front cylinder has spark.