My crane cams Hi4 system self distructed on me, was a single fire system. I put the stock sensor, ignition module, and coil back in. My question is: I have the accel hi output single fire coil, if I split the blue negative ignition coil wire into 2 wires into a Y, hook it up to both negitive terminals on the single fire coil so both coils fire at the same time, would it do any damage to the ignition module?

 

If I were in your shoes I would call the Crane Hi-4 boys and ask them this same question. I have seen several bikes that had bad electrical problems due to using the wrong coil. It might work for a little while but the coil will fail over time.

 

My experience with HI-4 is that they are for show bikes. They don't seem to last if you ride a lot. Mine was coil failure (twice). Never noticed ANY improvement in performance with single-fire. Went back to SE dual-fire, and it is reliable (years now).

What you are suggesting sounds like a future breakdown when it will be most inconvenient.

 

Totally agree , put a single fire on my 91 FLSTF and had nothing but problems with the hardware , coil went bad then the pick up unit behind the nose cone took a dump. Went back to the stock dual fire with a SE box(higher rev and better curve) and a SE coil, worked flawlessly. I would try to find a high performance dual fire coil if you think you need it.