Unfortunately on these bikes the coils are part of the spark plug wire. Its very rare for a coil to go bad, but it is common for the wiring to rot and the condenser to go bad. However both cylinders share the same condenser. Is it the same cylinder misfiring? Do you have a set of feeler gauges...
I'm too cheap to buy a BOV. I just ride with a massively fat chick in the car and have her slap her legs together when I shift. The massive air pocket that gets built up in those fat rolls works as good as a SSQV.