Electrical gremlins in '78 LeMans

[Ralph Plant]

Hello all
I'm having some issues which I believe to be electrical..not my strong suit at all! I have a Dyna 111 ignition and coils which I installed about 20 years ago and have never had a problem.. Now after I've been on the road a bit the engine will sputter a bit and then come back to life. It may do it once or it may repeat..not sure if its the system or is there an issue somewhere else.
I was told that it may be in the kill switch.
I don't really know where to start.
Anyone have a clue?

[PeteS]

Start with the kill switch. Just spray it with some contact cleaner while moving it back and forth. Switch gear was not their strong suit back then.

Pete

[Ralph Plant]

So I've been told..I'll give it a shot..
Many thanks!

[Antietam Classic Cycle]

All of the power to the ignition runs through the kill switch, and with a Dyna ignition, that's a significant load. Wiring in a relay is a good idea.

[guzzisteve]

Kill switch kills the coils, black & white wires I believe, usually.

[blackcat]

If this is the original wiring harness and you plan on keeping the bike, you might want to consider a new Greg Bender wiring harness and a set of relays he sells to addresses those switches. At which point I’d take the switches apart and clean up the contacts.  Realistically not a huge amount of money given that it is a LeMans.

[fotoguzzi]

If this is the original wiring harness and you plan on keeping the bike, you might want to consider a new Greg Bender wiring harness and a set of relays he sells to addresses those switches. At which point I’d take the switches apart and clean up the contacts.  Realistically not a huge amount of money given that it is a LeMans.

what he said…but when was the last time you checked valve clearance? Your symptom could also be tight valves.

[moto-uno]

 
  At least 35 years ago I simply threw out the original switches and wired in some from a Yamaha 650 Seca and they have been through
hell and back (250,000 kms) and continue to work flawlessly . Put the originals in a box (and pass on to some future owner) 

[Dukedesmo]

Whilst the switchgear on my LM2 worked fine (it was very low mileage and had lived indoors all it's life), it looked and felt flimsy especially the indicator (turn signal) switch so, in the name of reliability and continuity I replaced it all with modern (Ducati to match my other bikes) switchgear.


Will keep the original stuff in case originality is important to the next owner.

[PeteS]

My ‘76 LeMans still sports the original switchgear. The kill switch did cause a bit a grief this Spring but a little contact cleaner made it right. As far as replacing everything it all depends how much you plan to ride it. Mine is no longer a daily driver so I will stick with it until it falls off.

Pete

[blackcat]

Mine is no longer a daily driver so I will stick with it until it falls off.

Pete

Good point, you could just spray some DeOxit into the switch and hope for the best. I've never taken mine apart while on the bike to clean the contacts, if so I'd take it apart in an empty room with white paper on the floor to catch that little spring. Even then......

[PeteS]

Good point, you could just spray some DeOxit into the switch and hope for the best. I've never taken mine apart while on the bike to clean the contacts, if so I'd take it apart in an empty room with white paper on the floor to catch that little spring. Even then......

I used Deoxit with the switch on the bike. It cured the problem. I agree taking it apart could produce some unwanted surprises.

Pete