New Type BTH Magneto

[Jeremy Thurley]

I would like to set up my twin with a steady heart beat tickover, it drives me insane sitting at traffic lights for what seems an eternity, only to have the bloody thing cut out the minute the lights turn to amber. If I remove one spark plug whilst setting up the other cylinder for preliminary settings do I have to be careful to earth out the plug not in use? This is on a new type BTH Magneto.

 

[CarlHungness]

It has been many years since I installed my BT-H magneto and it is one of the best things I've ever done to my Shadow other than installing disc brakes. As I recall I timed the plot after deleting the ATD and putting on a new drive gear (ET48AS), turned the BT-H so the hole in the shaft accepted the supplied rod to time it, and that was it. I don't understand this removing one spark plug to set up the other cylinder. Possibly we're talking about the old original style BTH and not the new one with electronic packs that supply spark at low cranking RPM. My point is, if you want a trouble free, battery free magneto, I don't think you can do any better than the BT-H. My bike doesn't idle at its lowest RPM at a stop-light, my cable arrangement WILL allow it to idle at just a tick-over in some circumstances, but overall I run an idle that is just a bit quicker than tick-over. I haven't had the thing die at a stop light in years. The only problem I've ever encountered was self-made when a plug wire burned through due to it being up against a cylinder fin. You do note this is new type BT-H, but your set up doesn't ring a bell with me at all.