Triumphrat

aceaceca · 09-05-2007, 04:52 PM

Just got a T120RT. Previous and current Norton rider. Wanted a Bonnie since 1970 when none were to be had in London. This one turned up 4 houses away. Small world. It is unmolested original condition. Question?? Where is a wiring diagram available on the net?? Am in a quandry as it has a horn relay mounted under main tube. It had two horns on it but I am going the little single tweeter. Horn not working now. The relay is English. It has two brown/blue?? wires going to it and then two browns going to the horns. Four terminals total. I can figure it out but was wondering if this is stock. Non of the diagrams I look at in Haynes or the Triumph 500cc manual show relays for any years shown. Any input would be appreciated. It has the correct hi/lo switch and horn button on left side. Thanks Ron

jimballard · 09-05-2007, 05:45 PM

I believe that the twin "Windtone" horns were the standard setup on the Bonneville. All the others had just the single one. Try to get a good repair manual; repros of the factory ones are out there now. Also, get a copy of the parts book for your bike, it is invaluable for its exploded diagrams.

Great find, great bike...enjoy it!! Jim

retrobiker · 09-05-2007, 08:22 PM

Congragulations and welcome.I have a 70T120R,which probably has the same wiring .Mine came with twin horns(clearhooter windtone)that I think were made standard (with the relay)in 69.
I have the service manual with wiring diagrams and will be glad to send you a scan (if I can get my scanner to work-it's grumpy right now).I do need the engine number since there are different ones for the different models.
Enjoy the new bike.Would love to see a picture.

GrandPaulZ · 09-05-2007, 08:52 PM

aceaceca:

Welcome!

You have a limited edition RT model. If it really is a true RT and not a re-stamped bike, it has a pretty high value as one of a limited run in Triumph's first year of 750cc Bonnevilles for racing homologation.

The horn relay is correct for 69 & 70 with dual horns, the brn/blu wires are power, the other terminal should have a wire going to the horn button, brn/blk, I think. I'd better look at the diagram before I say any more, I'm probably goofing you up.

The bike should be a maroon-ish red called Astral red, with Silver scallops (possibly, several combinations in '70) upper, upper & lower, no scallops, but with a top stripe. I think the RT model might have been "correct" only with the upper AND lower scallops.

KADUTZ · 09-05-2007, 08:59 PM

welcome

the horn set up as described is the one used on a 70 T120 the relay should be attached to a light metal mounting strap and the frame. It may have a lucas part number of 33188 stamped on it.
If your horns (both ) do not work I would first suspect a bad ground or bad relay. I doubt both horns would go bad test each by running a jumper cable from a 12v battery if they honk you have a different problem.
if you want a single horn go for it.
BUT TAKE THE ORIGINAL HORNS RELAY AND MOUNTING BRACKET AND PLACE THEM IN YOUR SAFE DEPOSIT BOX.
By the way I also have an RT could you please advise what the first part of your VIN number is?

aceaceca · 09-06-2007, 02:06 AM

All is well. Horn button a little lazy. You were right. There is a dual wire br/bl on one terminal for power. A br/blk going to horn button on other teminal. This energizes the relay and feeds the other two terminals which feed dual horns via brown wires. Left relay in place but put one tweeter on. I am amazed that the haynes manual did not show a relay on any of 5or6 wiring diagrams.

Anyway finished up going over a lot of things on the bike to freshen her up. Still running points. Seems to be all stock. Has the right markings on the cylinder. I do not see a part number that has been referenced here. My serial number is CD43*** I don't quite understand why everyone is hesitant to give up their number but I guess I will follow suit.

Ran her around a bit. She pops out of 3rd and maybe fourth. Also the handle bars are not straight on when going straight down the road. Good idle and pretty good power o/p. My initial impression is that the Triumph is not near the machine the Norton is. I may be biast as I have had 4 Commando's over the years. Rode one I bought in England from New York to Houston and Houston to Los Angeles,so I have some saddle time on them. The fit and finish on the Commando is far superior to Triumph.

KADUTZ · 09-06-2007, 08:31 AM

your VIN number is in the correct series for the RT's Some people are nervious about posting complete VINs for various reasons. If you send me a PM I will check the partial list of RT VIN's I have and see if it is on the list.
I may not get it done for a week or so as we have the list in our bank box.

can you post a picture of the bike ?

GrandPaulZ · 09-07-2007, 10:05 PM

For what it's worth, it seems there are at least 2 or 3 "RTs" at the Mid-america auctions just about every place they go.

KADUTZ · 09-08-2007, 01:12 AM

That exactly why it is so important the AMA admit that the records exist.

The VIN numbers were recorded by the AMA for vehicle certification purposes. They HAD TO have these records and I believe still do as if someone wanted to race a bike how elses could they allow it to run as a factory racer?
The only way to prove a bike is,in fact, an RT is to see if the VIN is on the list. I have been VERY lucky not only do I have a letter from the AMA showing my VIN I also have ALL the originial papers on my bike. (These were given to me by the original selling dealer which is another RT story)

I will admit it is 'interesting' how often they show up at the auction. It is possible to tell a East Coast RT from a West Coast RT.

Mecchanica · 09-08-2007, 06:49 PM

The RTs used a specially machined Routt kit. The reliefs for the base nuts were flycut ala the stock bikes, instead of the way Routt machined his standard big bore kits for retail. There were spares made, a hundred or so, so someone could have found one and used it after restamping a standard 1970 Bonneville.
The AMA had no reason to keep those records, since most of the RTs were sold as street bikes, not as racers....that was the whole idea...that you could race the OHV 750 IF it was derived from a production (street) bike, even a limited production bike, and the cutoff the AMA specified was 200 units. I don't imagine many RTs got to the track. Racers just bought Routt kits and hotrodded their 650 racers which had been legal for a year, or built a new bike from scratch once the AMA approved the displacement increase. No point in buying a stock bike and tearing it all apart.
As long as Triumph certified that they had sold at least 200 750 kitted twins to the public, then anybody could race a 750 Triumph, regardless of year.