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Fitting a powerspark kit to a coil ign 99


I have a kit from years ago , did not work for me back then.  Thinking that my 99 has a 2MC capacitor fitted  ( not a standard fitting ) this could  affect the Powerspark  unit .   Any one done this ?.  Can't be bothered to contact the sellers as last time they did not know  sweet F A .


Why not hook up a tiny sealed lead acid battery to test it?



Hi Steve, I had the kit on and off too many times  and tried everything I could think of (appart from removing the 2MC !)    Even sent it back twice(at my expense ) and got a battered SH replacement in exchange. Never got a peep out of it.  No chance of a re-fund . Its just one of those "failed improvements"  that  leave a bad taste  and  would be nice to solve.


Which not disconnect the 2MC and connect a battery for test purposes?

Test it in exactly the way it was intended to and change one thing at a time.




Hi Steve, The bike is going and starting  well at present with points  although it has a carb fault that  turns the plugs very black and sooty . If the ignition was not strong it would be missing and not starting what with the plugs in that state, so I'm reluctant to  play with alternative ignition untill the carb is sorted. That in itself is proving to be a puzzle. It runs  cleaner with  old worn out parts fitted (just the opposite  to what I would expect) .If I weaken off  settings it won't run well  or start and shows all the symptons of weakness except the plugs stay sooty .    May  try a change of  carb .body, A fellow Norton nut  has offered one to  experiment with. Not keen on new parts as they seems to bring more troubles.


The sooty plugs could very well be oil.

The 2MC or its equivalent are only there as a battery 'make do'. It is always best to fit a battery but a small one will over charge so 5AHR is recommended as the smallest. The 2MC (as fitted to Commando and Mercury and late Atlas from the factory) was ostensible to give some sort of emergency start with flat or even non existent battery. They were normally only fitted to 12V systems. IF they were specified with some ignition system it was probably an ignition system that was intended to work without a battery. So as Steve says fit a battery to run it on, But is the Dommie already running on12V in which case ignore reference to 2MC.

I am very happy to test such an ignition. Does it retain the points Hence just a current amplifier or does it fit withing the 18D2 in some way? or is it a separate pickup housing with some form of pick up ie magnetic, infrared, or Hall effect?


Hi Alan,  The Bike has always had a full sized battery, The 2Mc is there to allow flat battery starting as the PSR8  allows fiddlers to switch on lights  and the 99 was used to swop batteries with a non charging racer, and a charging point for 3/4 mobile phones overnight  and had to be able to cope with a flat.battery. The Powerspark kit has a magnetic trigger that fits below the rotor arm and a  EI block that replaces the points.  Some wiring alterations were needed. If you are interested I will post the gubbins for you to evaluate .  I did notice that turning the engine over very slowly only supplied current to the coil for a fraction of a second, which is alien to me but probably normal for EI.


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