I'm closing in on completing the restoration of my 1966 T120R, and finally got around to reinstalling the horn. This is the original Lucas 8H, and it seems in good shape except for its refusal to make noise.
Unlike the earlier Altette, the 8H is riveted together and perhaps not intended to be serviced - but it's easy enough to drill out the rivets and poke around. Before I do, is there anyone who's done this and has experience to share?
(I know there are millions of replica/substitute horns available, most of which work - but I want to keep the original 8H if possible.)
i did it.........drill out rivets...carefully pry apart the two halves...there are points in there like Lucas fuel pump points...clean points...clean out dirt etc. inside shell...there is a little piston that might be frozen in there...use a little dab of WD40 to clean it so it moves freely...it moves up and down in response to electrical impulses and makes the diaphram move up and down and that makes the noise...put a teeny smear of silicon on the halves and bolt them back together with little tiny bolts and nuts... you adjust the sound with the screw on the back...hook it up and push the horn button and turn the screw til it is at the loudest .......to tell you the truth i was not impressed by the bleeting so i got a horn off eBay for $10 from a Hinckley triumph and painted it flat black and hid it under the steering head on my A65 and it is loud and shrill and the Lucas one is just for looks........PS google Taffthehorns.com
David: I have restored many sets of Clear Hooter Windtones, and they are also riveted together. I have found that using drive rivets work very well and the heads look like the original rivets. Drive rivets have a rivet head and the shank has a spiral type thread that screws into the housings. Drive rivets are easily available. I even powder coated the rivet heads before installing the rivets...now that is way over the top. Good luck
Thanks to all for the input. I opened up the horn, and found all it needed was for the points to be cleaned with fine sandpaper. It's back together, on the bike and works. As a bonus, it polished up pretty well - I thought I'd have to replate it or paint it. Here are some pics: