early tailight on an 850

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britbike220 said:
Hey Dave, I think something could be done as well, but like I said I don't have the tools to fabricate custom parts. Here are a couple of pics I added to the others of both lights together. The 750 is longer, but where they go over the loop is about the same distance. Looks like the big difference is length off the back where the lens is. This would cause the extra weight and stress.

http://community.webshots.com/album/577899521yOdszS
Click to expand...

Great pictures! Sorry you use Webshots. :wink:

early tailight on an 850

So... to put the 750 light on the 850 fender wouldn't you just use the forward two bolts and then the lower two on the license plate bracket? It seems like a bad compromise but it would work, no?
 
I opened a webshots account a few years ago and never checked anything else out and post pics of bikes and crap once in awhile. I think unless the 75- housing is secured good and tight the vibration will destroy the new tail light housing. I think the plate bracket is going to self destruct anyway, very cheap and flimsy in my opinion. I know what kind of bracket may work, home made and simple, but like I said I don't have a lot of fabrication tools. If I can find some good thin steel plate I will try and make what I think will work up. Even though I found an extra fender I think it would be good practice to make a bracket for future owners to possibly use. A simple single piece of metal bent right with three holes drilled will work, I think. Maybe I can make a mock piece up out of aluminum to see if it'll fit.
 
Here's another option for you. This is a copy of the Bates tail light housing that I bought from Old Britts a few years ago. It came unpolished and I polished it myself. You might be able to buy an original on eBay. The tail light unit is a copy of the Lucas 564.

early tailight on an 850


early tailight on an 850
 
I wish I'd of seen a picture of that installed before I bought the 750 parts. You have a picture of the whole bike from the side?
 
britbike220 said:
I wish I'd of seen a picture of that installed before I bought the 750 parts. You have a picture of the whole bike from the side?
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early tailight on an 850


early tailight on an 850
 
That is a beautiful norton.......I had some 1" strips of 14g sheet metal cut today and think I can get by with drilling one smaller hole centered below the original mount hole. Beats trying to drill two perfect holes in my stainless fender. I will have to make a recess in the fiberglass for the bolt head to sit in so I can get the bracket radius to form close enough to draw the fender in.
 
OK I have a bracket made, an extra stainless fender and finally the screws I was waiting on to put my 71 tail light on my 850. Now I have a wiring question. The original tail light has three wires and the replacement 71 tail light has only two. I can either have a tail light or a brake light, but not both with the two wires. The third wire on the original looks to be a ground only, but I don't get how I am suppose to get a brake tail combo with two wires? Help anyone?
 
britbike220 said:
OK I have a bracket made, an extra stainless fender and finally the screws I was waiting on to put my 71 tail light on my 850. Now I have a wiring question. The original tail light has three wires and the replacement 71 tail light has only two. I can either have a tail light or a brake light, but not both with the two wires. The third wire on the original looks to be a ground only, but I don't get how I am suppose to get a brake tail combo with two wires? Help anyone?
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I'm guessing on your wire colors but I'd say the Brown/Green is the Tail Light Circuit and the other wire is the Brake (it might be Brown).
 
britbike220 said:
The third wire on the original looks to be a ground only, but I don't get how I am suppose to get a brake tail combo with two wires? Help anyone?
Click to expand...


I think the early bulb holders only ground through the actual tail lamp unit itself, and the later tail lamps have "proper" ground wire, check how the two tail lamp wires connect to the bulb holder, as the tail lamp assembly should still have a double filament bulb holder with two insulated bulb contacts?

I suggest you run an additional ground from the tail lamp assembly back to the harness or other ground point?
 
L.A.B. said:
britbike220 said:
The third wire on the original looks to be a ground only, but I don't get how I am suppose to get a brake tail combo with two wires? Help anyone?
Click to expand...


I think the early bulb holders only ground through the actual tail lamp unit itself, and the later tail lamps have "proper" ground wire, check how the two tail lamp wires connect to the bulb holder, as the tail lamp assembly should still have a double filament bulb holder with two insulated bulb contacts?

I suggest you run an additional ground from the tail lamp assembly back to the harness or other ground point?
Click to expand...

Yes, early ones ground through the tail lamp.
 
Re: early tailight on an 850 (new wiring ?)

You would think for the money vendors charge they'd supply the right wiring and the part would somewhat fit without modification, but welcome to pattern parts from china. I'll try running a ground from the lamp housing to the harness like the original.

I supplied an extra wire and it works now, thanks guys. Hopefully I'll have it on today.
 
Re: early tailight on an 850 (new wiring ?)

britbike220 said:
You would think for the money vendors charge they'd supply the right wiring
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They did,- didn't they? :?

If your early style tail lamp has no ground wire-then it's got the right wiring!
 
Re: early tailight on an 850 (new wiring ?)

L.A.B. said:
britbike220 said:
You would think for the money vendors charge they'd supply the right wiring
Click to expand...

They did,- didn't they? :?

If your early style tail lamp has no ground wire-then it's got the right wiring!
Click to expand...

If he has an aftermarket tail light (like I did) then the wires are black and red.

But that is acceptable as that tail light fit many bikes, not all of them using the Commando color scheme.
 
Re: early tailight on an 850 (new wiring ?)

Dave I think I have the same black/red wired housing you have, but I had to add a third wire grounded to the lamp housing as LAB described? At any rate it works with the extra wire and I have everything made so I hope to have it on today. I really don't think the cheap thin plate bracket is going to last long with vibration.
 
Re: early tailight on an 850 (new wiring ?)

I didn't want to drill my rear fender either, but definately wanted a Lucas 679 taillight on my '74 MkIIA. I removed the original tail light and mounted the 679 backing plate on my original DOT mandated way oversize taillight bracket where it looked right to me, I scribed around the top of the 679 backing plate, then I cut off the top of the original mounting bracket to match the shape of the new tail light. I filed and sanded it smooth and repainted it. Then I installed the fiberglass fairing on the bracket and cut it back so it was as close to the size and shape of the 679 as I could get it. I then used styrofoam to fill in the small gaps between the cut off part of the fairing and the recut bracket and sculpted the foam to contour everything together into the 679 shape. The foam just served as a mold pattern, and I sanded it smooth and layed up 3 layers of fiberglass and epoxy over the foam and the remains of the original fairing. After it set up I removed the foam from the under side of the fairing, sanded and smoothed up the new 'glass and primed and painted it. The bracket bolts right up to the fender just as it did originally, holds the much more pleasing to the eye Lucas 679, looks like a factory piece, and if I ever want that big wart of an original tail light back on, all I need is a stock '74 bracket and fairing. Of course if I had known of the CNW or Old Britts brackets I could have saved a bunch of time.......
 
Re: early tailight on an 850 (new wiring ?)

flyboy49 said:
I didn't want to drill my rear fender either, but definately wanted a Lucas 679 taillight on my '74 MkIIA. I removed the original tail light and mounted the 679 backing plate on my original DOT mandated way oversize taillight bracket where it looked right to me, I scribed around the top of the 679 backing plate, then I cut off the top of the original mounting bracket to match the shape of the new tail light. I filed and sanded it smooth and repainted it. Then I installed the fiberglass fairing on the bracket and cut it back so it was as close to the size and shape of the 679 as I could get it. I then used styrofoam to fill in the small gaps between the cut off part of the fairing and the recut bracket and sculpted the foam to contour everything together into the 679 shape. The foam just served as a mold pattern, and I sanded it smooth and layed up 3 layers of fiberglass and epoxy over the foam and the remains of the original fairing. After it set up I removed the foam from the under side of the fairing, sanded and smoothed up the new 'glass and primed and painted it. The bracket bolts right up to the fender just as it did originally, holds the much more pleasing to the eye Lucas 679, looks like a factory piece, and if I ever want that big wart of an original tail light back on, all I need is a stock '74 bracket and fairing. Of course if I had known of the CNW or Old Britts brackets I could have saved a bunch of time.......
Click to expand...

Um, pics?
 
Re: early tailight on an 850 (new wiring ?)

Well I got it done looks good except it appears to dip down a bit, not bad, but I notice it. In my mind it should come off the fender straight out w/o a dip. If the holes were drilled different I think it would look better, but I guess when converting something there can always be something a bit out of whack. I ended up making two extra brackets for the plate to mount to the narrow plat bracket provided. It started storming so I couldn't take a picture. I'll try and post one Saturday. Guys I thank you for all of the input.
 
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