Mark, What a great thread. I read it from the begining to end. I just bought a 1977 CB550K Sunday and am looking to get it in top shape. It runs well but needs the stock airbox back on (only runs w/ choke on now w/ the velocity stack). I want your Transistorized Ignition. Since this is a new bike to me, what should I look for to make sure there is no aftermarket on it that might cause issues? I did find a switch behind the side plate that turns the headlight on and off. I guess that is to save power???
Mark will jump in to help but until that comes along I'll make an attempt at some info for ya... I'm a very happy user of his ignitions. They do so much to help the bike run better. In terms of your headlight, the best setup is to use a relay to do the heavy lifting of the power to the headlight instead of forcing the power through your ignition switch. The ignition switches (and especially the aftermarket or replacement versions) can fail over time because of the big load of the headlight. You might also consider taking the load of the coils off of the ignition switch.
This is all done by operating relays with the ignition switch that control the coils and the headlight thereby removing most of the load from the ignition switch and allowing you to run a "larger, more reliable pipe" of power to those components. When I say "larger and more reliable", I mean switches that were intended to take that load (or more) and heavy enough gauge wire.
Some will argue that the factory setup is adequate but these 40 year old bikes are not in "factory condition". Even in factory condition (all connectors and switches in perfect condition), I think you'll experience higher voltage at your coils and headlight (more spark and brighter headlight) using a relay system.
It so happens that Mark sells kits to make this conversion (or you can do it on your own) and your ignition switch will be "happier" for it.
John
