Sport 750 Headlight assembly

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Bern
Parallel Twin
Posts: 100
Joined: Thu Jun 10, 2010 7:29 am
Location: Toronto, On Canada

Sport 750 Headlight assembly

Post by Bern »

So my fiberglass gauge holder literally cracked in half from the vibration after hitting a pretty deep pothole on my 74 GT. It looks like a previous owner had done some sort of epoxy repair and it gave out. So my 74 GT which looks more sport than GT at the moment might start looking a little more like a sport. I'm going to do away with the instrument cluster and pick up the sport type gauge holders.

I have a question about the idiot lights and the main light switch that are mounted inside the headlight on the sport. If you look at the online parts diagram for the GT and Sport, parts 340 and 343 which are held in place by the nuts for the idiot lights serve to keep the main light switch in place on the GT. I don't see what is doing this on the Sport. How is this switch held in place? Do I need to fabricate a holder?

Part 355 the threaded tube for the alternator light appears to be too long and will push against the bulb. With the fiberglass it wasn't a problem but in the headlight the housing is not nearly as thick. I'm worried about the grounded tube making contact with the light and shorting out. Are there external washers used on these idiot lights that provide more spacing? I'm guessing not as this would make the middle light look different then the others. There doesn't appear to be any on the parts diagram. If anyone has done this did you just file this tube down?

Also these openings for the idiot lights seem like ideal entry points for water. Is this an issue with the Sports?

Any help or photos of the inside of the headlight would be much appreciated.

Cheers,
Bern
machten
MHR / S2
Posts: 478
Joined: Sun Oct 29, 2006 8:37 am
Location: Perth, Western Australia

Post by machten »

Bern,

I can't help you much with the conversion, but have included some photos of my Sport headlight internals. This wiring is not original and has been done by a previous owner but it's never given me any trouble, so I've just left it alone. I've certainly never had any issues with water getting through the idiot lights holes, but I don't ride in the wet if I can avoid it.

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Kev
Bern
Parallel Twin
Posts: 100
Joined: Thu Jun 10, 2010 7:29 am
Location: Toronto, On Canada

Post by Bern »

machten wrote:Bern,

I can't help you much with the conversion, but have included some photos of my Sport headlight internals. This wiring is not original and has been done by a previous owner but it's never given me any trouble, so I've just left it alone. I've certainly never had any issues with water getting through the idiot lights holes, but I don't ride in the wet if I can avoid it.
Kev

Thanks a lot Kev.

I appreciate the quick response. Do you know what is holding the main light switch in place? It looks like it could be a couple of rivets. Is the black piece under the switch touching the headlight a rubber grommet or is it the hard bakelight that's part of the switch?

It looks like the part with bulb(middle light) is held far enough away due to the curvature of the headlamp housing. I guess the trick would be not to over tighten the nut holding it in place. I still might take it down 1/8 or so.


The wiring is pretty straight forward so I'm not worried about that. It was more that I got the switch looking like it should on the outside for the sport.

Again thanks for the pics it really helped for the positioning of everything.

Anyone have any tips for cutting the hole for the switch? Asides from being careful with a dremmel tool. :-D

Cheers,
Bern
machten
MHR / S2
Posts: 478
Joined: Sun Oct 29, 2006 8:37 am
Location: Perth, Western Australia

Post by machten »

Bern,
Do you know what is holding the main light switch in place? It looks like it could be a couple of rivets. Is the black piece under the switch touching the headlight a rubber grommet or is it the hard bakelight that's part of the switch?
OK, get ready for a chuckle...

Look at the third photo above. At the 12 o'clock and 6 o'clock position you will see angled metal lugs that are steel rather than the brass wiring connectors. These lugs are welded/braised onto the headlight body. Now look at this photo below of a switch...

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The lugs appear to basically be pushed through the relevent slotted holes at 1 o'clock and 7 o'clock and then twisted to hold the switch in place. (What can I say????). Bear in mind the assembly that passes through the headlight body is not round and that part takes the twisting torque, not the lugs (see below).

Image

I can't see anything other than the bakelite/plastic in my setup, but that may or may not be right.

Kev
Bern
Parallel Twin
Posts: 100
Joined: Thu Jun 10, 2010 7:29 am
Location: Toronto, On Canada

Post by Bern »

That's perfect. I'll try to get a couple of stainless fasteners for now. The headlamp body on mine is painted so I'm not going to be applying any heat. Thanks for all the help..
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