You'll probably need to use a separate 12 volt battery to power the timing light. It's been so long since 6 volt systems were used, it's not likely any of the modern lights will work on 6 volts. No problem, just use a separate battery and connect the timing light power leads to it.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!