M66 Overheating Ignition Switch

[Scott E]

Problem resolved. A new ignition switch sorted it out. It must have been shorting somewhere, though I couldn't spot the problem with the old switch. the contact in the new switch doesn't even get warm when the ignition points are closed and the bike runs fine.

Switches have contact 'points' just like the points in your points type ignition system. They do wear out and burn up over time. Of course no where near as fast as the ignition points seam to pit and wear out but it's good you solved that problem.

As for the generator, you may want to open it up and check the commuter where the brushes ride. The copper lands can tarnish from disuse preventing the transfer of voltage and current to the field windings. If tarnished you can clean the copper with Emory cloth and make them shiny again and transfer power. Also look at the area between the little copper pads. Carbon can build up between them and cause problems. A thin blade flat screwdriver tip can be used to clean them out. Just drag the point of the screwdriver down the little slot and the carbon dust and dirt will come out. If they are badly scared or worn if you know someone with a metal lathe you can cut a few thousands off the surface to make the commuter like new again. When I was a kid auto parts stores had small lathes designed just for turning generator commuters to resurface them. Back then you would just take your armature shaft in and a few minutes later and your wallet a dollar lighter you had a nice fresh commuter again.

[Scott E]

there are wee black boxes out there that send micro voltages to the points ..i put one on the Dnepr an didn't look at the points after :)

I'm in the process of building one of those for my old tractor. It's got an antique Kohler engine with points so there's no way to put an electronic ignition kit on it. It will incorporate an IGBT transistor designed to drive an ignition coil and with another small switching transistor along with a few resistors and a capacitor you can hook it up to the points and use those to trigger the transistor that drives the coil so the points will pretty much last forever. The transistor is a FGP3040G2-F085 which replaces the now obsolete IRGB14C40L.