Topic: Horn refurbish

[upperlake04]

Hi All - just received my new old horns/emblem won on eBay for the 78 750F resto( 77F horns).  Seller stated the unit was checked over and worked well - but on the bench I can't get a peep out of either horn   I suspect he was was BSing me.  So before I start whining to the seller,  is there a method to check the electricals or somehow kickstart these. Both seem to have some resistance with my $5.00 multimeter.  I've twiddled the volume? screws and smacked the backs - nothing.    The cases don't seem to be openable.   Yes, my battery is charged        Anyone with a horn starting trick?

[number13]

To my knowledge there is no way to refurbish horns, they pretty
much either work or not. Sometimes twiddling that screw will make
it sound louder, but that is all that will do.
I'd say you have a legit beef with the seller on this one.

[flatblack]

If it's offering resistance, it's probably just corroded. Get something like Corrosion X and liberally spray the interior. Let it soak in. Betchya it'll work...

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[KB02]

You could also just jump them right off of the battery. I've done this before to check a horn. If it's gonna beep, that will be when it will beep.

[dusterdude]

find a good battery and ground the frame of the horn to the neg terminal and run a wire to the pos terminal on the batt to the horn terminal.

[upperlake04]

OK - with nothing to lose with my four non-operational horns, to see whats inside, I took the worst looking one and ground off the ring that holds the halves together.  Pretty simple and not much for moving parts. Didn't have any Corrosion X so I poured some Canadian Tire rust remover (phosphoric acid)  through the big mounting hole in the backs of the other three. Rinsed, dried, and two of them came to life. So it looks like I will be able to get a working set from the pair.    Thanks all

[nickjtc]

Didn't have any Corrosion X so I poured some Canadian Tire rust remover (phosphoric acid) ...

What is the actual product name in Crappy Tire? Thanks.

[upperlake04]

Nick - Motomaster Liquid Rust Remover 47-7923-2.  The container has been in my shop for a few years so I don't know if the product name and part number will still be the same, but I expect they will carry something similar if not. Automotive section.

[Jonesy]

Most of the time horns are rendered inoperative from bad corrosion/pitting of the contact points. The phosphoric acid probably cleaned them up enough to make them work. Just make sure you didn't destroy any of the other pieces inside. I was working on the horn for the CA95 and got it working again, only to have the fuse blow every time I'd turn the key. The horn had developed a direct short to the frame. Now I have to tear it apart again and fix the missing piece of insulation....

[upperlake04]

Hmm, hadn't thought of that Jonesy.  Figured it was either the crudded points or the center metal 'plug' that seemed to  free up a bit after the treatment. Will have to reinstall on the bike to see if they are really fixed...

[nickjtc]

Nick - Motomaster Liquid Rust Remover 47-7923-2.  The container has been in my shop for a few years so I don't know if the product name and part number will still be the same, but I expect they will carry something similar if not. Automotive section.

Thanks

[techy5025]

The decibels that most of these old horns put out could be bested by someone with bad
gas pains.  Put on a set of air driven boat horns...that will make the cagers look up.

Jim

[nickjtc]

The decibels that most of these old horns put out could be bested by someone with bad
gas pains.  Put on a set of air driven boat horns...that will make the cagers look up.
Jim

And a loud horn is way more selective than riding with loud pipes.........oops, opened up that can o' worms again!