Suzuki GSX650F Forum - www.GSX650F.biz

Installed a stebel air horn (the semi waterproof type) on the 1250FA. Had to make a small mounting bracket out of some cheap metal from Bunnings hardware that had good tensile strength. All you do is bolt the bracket onto the bike, bolt the horn onto the bracket and twist and push the horn around to position you want, ie not touching the forks or the fairing. Take note of where everything is, the take horn and brackets off, and rustproof the brackets with some sort of rust paint, (I used rust paint and then put electrical heat shrink wrap around the brackets).
I installed it on the left side of the bike and to keep most of the wiring simple and short (I used 4mm 20amp automotive wire, Black for negative, red for positive, keeps it simple.) I attached the stebel relay that comes with the kit onto the horn with another small bracket. the only long wire will be the positive wire from the battery.
You must install a relay with this horn. If you don't, and just attach the original horn wires straight onto the air horn, you will destroy the horn button contacts up in the switch block on the handlebar.
Also, buy a waterproof 20Amp fuse holder and install it close to the battery (see later pictures). I found that the best place is under the left hand side panelbecause its easy to get off if you do blow a fuse. Go crazy with the pull ties when putting your wiring in so no wiring touches anything hot. I just ran my main positive wire along the main wiring loom from the battery to the horn relay.
The newer model stebel horn has a better mounting system than the older models, but I still find that pull ties wraped around the horn and onto the frame give you better peice of mind that the horn isn't going to go "walkabout" inside the fairing somewhere they are also easy to cut off and cheap to replace when services of the bike may reqire the horn to be removed.
To stop the bolts from vibrating loose you can use lock washers or locktight fluid on the threads. This model stebel seems to point more forward than the older model. I like to leave the original horn on the bike just in case the relay or stebel air horn dies. Then all I do is pull the original wires off the relay and put them back onto the original horn.
With the horn installed this way you lose a tiny amount of volume from the air horn but its such a small amount I woldn't worry.
As i have said before remember that with this installation when you want to change your spark plug in number 1 cylinder you will probably have to take the horn off. Its not hard to do, but if you get the bike seviced at a dealer or bike shop they might stuff up the reinstallation of your horn. So I would take the horn off the bike before having the more comlex services. Thats another reason to leave the original horn on the bike as well.
Have fun.

A few more pics of the install.

I very rarely use my horn. I used it the other day and was embarrassed by the sound that came out of it. I increasingly wish I had something like this to scare the b'jesus out of drivers drinking coffee and making phone calls.

A bit more of the wiring. and a simple wiring diagram.

Slight change in wiring diagram. Stebel horn and relay bypass switch install. Just in case stebel horn or relay dies.

Great wiring diagrams, with I had them when installing mine.

I have a Yoshi road- Ilegal beast of a pipe, a powerbronze double bubble screen, a K&N filter and a Stebel Nautilus... which do you think is my favourite mod?

the deafening Stebel Nautilus without the shred of a doubt... I ride around just looking for some jackass to mess with me then I unleash the 136 decibels and burst out laughing 5 seconds later