Why are the mounting bolts for the rear tail lights different sizes ??!!

[Hillbilly_Rider]

New here, first post, I've recently acquired a mint 79 XS Eleven, long story short , the elderly gentle man I got the bike from had removed the rear signal lights for aftermarkets (don't ask) was relacing the originals and discovered the bolt for the right side (the hollow sleeve) was missing, actually found one at a small nos place in MI, received the part and it's to small, took the one out of the left side and tried it, to small, after much hair pulling and searching old biker buddies junk parts, then a trip to Grainger to discover I need a 12mx1.25 not a 10m , I've said all that to ask this, does anyone know why it's like that and DOES ANYONE HAVE ONE ??!! I would gladly pay. Will post pics of the unicorn I found , I'll say this 3,388 original miles.

[DEEBS11]

Which bike? Standard or Special?

[DEEBS11]

Is this it?

[jetmechmarty]

Those pieces are longer on the front stalks than those applied to the rear on a Special.

[Hillbilly_Rider]

You mis-read my post, it's not the length, it's the diameter, the bolt pictured is a M10 (and I ordered one from NOS, that's what started this journey), I needed and M12, I got it fixed, had to give a machinist buddy a call, and drill a bolt out & cut it off, if there's one thing the Marine Corps taught me was Improvise, Adapt & Overcome. Still have no explanation on why my right rear tail light is different than my left & different from every schematic I've seen ( believe it or not, we do have internet up the holler) or manual I have, oh well, it's fixed & working, moving on to other wiring issues, swapped out the reserve lighting relay, still no headlight, any suggestions?

[DEEBS11]

You larger 12mm was obviously a repair of the stripped original 10mm. Signal lights are the first part to be damaged in a fall which is very common. However, the drilled bolt sounds like a good repair.

[DiverRay]

Headlight will NOT come on until the engine is running on these bikes. I would start with all the GROUND POINTS for the wire harness. Clean all connections, and with the spade or faston connectors, squeeze the female side just a little bit to get a more secure connection. Don't forget the frame to engine ground cable, as it's sometimes the biggest problem due to rust on the frame.

[bikerphil]

There is a headlight relay located under the tank towards the steering head on top of the ignition coils. It has 4 wires. If you unplug it and in the connector, jump the red/yel and blu/blk, the headlight should come on with the key in the on position. The RLU that you tried replacing (black box near voltage regulator) only directs the current from one filament to the other in case one burns out. As stated, the engine needs to start to activate this relay.

[Hillbilly_Rider]

Thank you so much, needed to know which to jump to check circuit , off hand question, if the stator isn't charging will the headlight work ? I know some of the older bikes ran stuff through the headlight.

[bikerphil]

If there is no current coming from the alternator, the relay won't latch and no headlight.

[DEEBS11]

Here is the circuit.

[DEEBS11]

Here is how you get rid of it.

[DEEBS11]

Here is how you get rid of the reserve lighting unit.

[DEEBS11]

Low beam......

[DEEBS11]

High beam......