Forum

[NicoV]

Is there anyone here who converted his Bullet to twin spark, and use the decompressor as on the Electra (which lifts the exhaust valve). I wonder if it is worth the cost.
Hitchcock's kit for the valve lifter is not expensive, but it also envolves having a twin lead coil.

[Bullet Whisperer]

Hi Nico, unless you just want a talking point, I wouldn't bother. Our 350 racer hits 9500 RPM, only uses one, none resistor, bog standard, ordinary spark plug and manages pretty well. Regards, Paul.

[jefrs]

Where "twin spark" comes into its own is like on a Mercedes-Benz where the two sparks are on different and variable timing, they also have variable valve timing. Indian petrol is putting it politely rubbish, which is why they have two plugs. I did some research digging, found some numbers I won't bore you with etc - NGK recommend using resistor plug with resistor cap, this provides a better load on the secondary of the stock coil to give a fatter spark of slightly longer duration (2 millisecond); this to provide better ignition across the entire operating rev range. H can also supply heat proof silicone HT lead that doesn't get cooked to death on the rocker covers. The HT lead screws into the mysterious EFI coil (it looks bonded in) like it does on the HT cap. Paul (Bullet Whisperer) is running a race machine, different animal.

[Revband]

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