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Horn

Posted: Fri Sep 17, 2021 2:34 pm
by frankfast
Anyone know if a horn can be rehabilitated? Have a Bosch horn that is sealed and has a small screw at the back. I can get a small sound when screwed outward but nothing when screwed in. Is it trash?

Re: Horn

Posted: Sat Sep 18, 2021 12:19 pm
by Ventodue
Yes, they can. They're very simple devices - plenty of info on Tinternet; just type in, 'How does a high frequency horn work'. It's often just the points inside. (The screw on the back acts on the points to compensate for wear).

Is it worth it? Ah, that's a different question ...

Fun, if you like fiddling. But if you just want to get street legal, it's might be better to simply fit a Chinese one off eBay or wherever. More reliable, less energy consuming and certainly louder ...

Btw, to the best of my knowledge, Ducati singles didn't use Bosch units, but CEV (various models); and possibly Aprilia. But, as always, I stand to be corrected.

Re: Horn

Posted: Sat Sep 18, 2021 8:49 pm
by frankfast
Thanks Ventodue. The horn I have is supposed to be original equip on my F1 which is the only reason I was interested in it. I have a cheap aftermarket item that works fine but I wanted to know if anyone has taken one of these things apart. It looks sealed to me and would be destroyed if I tried to open it. It also weighs twice as much as the aftermarket one.

Re: Horn

Posted: Sat Sep 18, 2021 11:06 pm
by Jordan
I haven't had much success with horns.
An early mistake was to use silicone gasket paste instead of the main gasket, and I think it was pretty good at reducing sound.
Keeping water out is important of course.

Voxbell is another brand of horn I've seen on Ducatis.

Re: Horn

Posted: Sun Sep 19, 2021 10:23 am
by Ventodue
frankfast wrote:Thanks Ventodue. The horn I have is supposed to be original equip on my F1 which is the only reason I was interested in it.

Got you. Does it look like this?

Bosch horn.jpg

These Bosch units were original fit on late bevels (MHR, Dramah etc) and also on the 500 and 600 Pantahs, all the time under part number 0801.38.050 (0801. is the Dramah model code).

So very likely fitted to the F1 too, but I haven't been able to confirm the part number for the F1.

Personally, if it ain't working, I don't think you have anything to lose in trying to carefully prise the thing apart .... ;) . But first make sure you give a real good blast from a fully charged 12volt battery.

Re: Horn

Posted: Sun Sep 19, 2021 10:30 am
by Ventodue
Jordan wrote:An early mistake was to use silicone gasket paste instead of the main gasket, and I think it was pretty good at reducing sound.

Yep. In the absence of proper gasket paper, a bit of thick paper is all that's needed.

Jordan wrote:Voxbell is another brand of horn I've seen on Ducatis.

Ah, good point. In 6 volt as well as 12v, Jordan?

Also, I recall some of the 750 & 860 bevels had "Belli" horns. ("Who they?", you might well ask ...)

Re: Horn

Posted: Sun Sep 19, 2021 11:14 am
by frankfast
Yes Ventodue. That is the horn I have. Maybe I'll take your advice and try to pry it apart. Nothing to lose.

Re: Horn

Posted: Sun Sep 19, 2021 11:24 am
by frankfast
By the way, The F1 has an elephant on the tank. So it is a Cagiva part number, not Ducati.

Re: Horn

Posted: Sun Sep 19, 2021 3:04 pm
by Ventodue
frankfast wrote:By the way, The F1 has an elephant on the tank. So it is a Cagiva part number, not Ducati.

Ah ... a 1986 model then. The only F1 parts book I have is the 9-85 edition, still under the Ducati imprint.

I've never seen a Cagiva F1 parts list.

Re: Horn

Posted: Sun Sep 19, 2021 4:30 pm
by frankfast
Right, it's an '87 (laguna Seca) and the owners manual is Ducati. I've never seen a Cagiva parts or workshop manual either. But there wasn't much change from the earlier '85 bikes but still.