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Good suggestion but the blurb put out by the Fastbikegear (FBG) people suggests that coil sticks work fine with injection systems, they have a lower intensity spark (c20,000 volts) than “proper coils” (25 to 40k volts) and they work because the fueling is much more precise across the rev range. FBG did not say directly that coil sticks would not work on a carbie -just not part of their recommendations to get the optimum from their kit.
It is obviously a lot more complicated than that because even though the ignition trigger has said it is time to spark, the spark will only jump the gap when the air space between the electrodes reaches a certain ionization state (related I believe to the potential voltage threatening to jump the gap). The richness or otherwise of the fuel mixture and the load under which the engine is operating also affects this (worst case is with wide open throttle at low revs). With a fuel injection system the throttle position sensor in conjunction with the ECU which is also monitoring revs adjusts the timing of the spark to optimize the effectiveness of the burn (and in the certain knowledge that the coil stick can only deliver 20k volts).
With carburetor bikes the fueling is much less likely to be a precise / ideal air fuel ratio of 12.5 to 13.1 :1 and for the spark to actually jump outside this range and burn the mixture completely it needs and benefits from the higher voltage which is able to overcome the sub optimal sparking and burning conditions.
The ignition system I have bought includes an ignitech box which has a take off for a Throttle Position Sensor (TPS) and FBG state in their blurb that fitting a TPS to a carburetor M900 is a really worthwhile mod giving much snappier mid- range and take off from low revs.
I may consider this modification after I have got the thing running but from memory the space around the cable quadrant is heavily congested and I might take the view that it is just something else to go wrong. ????
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