Modern Vespa

Enclosed is a step by step walk thru outlining the installation of the Stabel Nautlis Compact air horn in Vespa 250ie GTS. The installations instructions should be similar to all Vespa GTS models.
The walk thru is separated in 3 parts:
1. horn disassembly
2. Air horn/relay mounting and airhose connection
3. Nozzle mounting

Note: the wiring is not shown as there are plenty of threads on proper wiring, points to remember:
1. run 10 to 14 gage wire from battery to relay. I used 10 gage since I'll be drawing the power for heated clothes.
2. Use female spade connectors + wire shrink wrap on all connectors
3. use the OEM horn wire to the stebel horn relay. The horn on wire is not in the alarm socket
4. Dielectric grease all connections


Stebel Airhorn, comes with relay. Don't get the airhorns from Italy. Their connections are different and can not be modified


out of package


need to pry airhorn from exit nozzle here


slides off like this


need to measure nozzle inlet hole diameter


use Ball gage


measure with calipers right at .353 inches


measure air horn outflow nozzle, at .340 inch


fit the air horn right in this cavity....Make a electrical panel to attach the horn and relay. See the how-to for instructions:
Vespa GTS electrical accessory panel install step-by-step


attach airhorn to electrical accessory panel mount


attach relay...2x shown one for airhorn, one for heated jacket/gloves (another pitch)


measure distance from airhorn to panel


cut rubber stopper to size


mechanically attach stopper to electrical accessory panel


airhorn rest on stopper for support


don't need the nozzle attach brackets, best to remove them


cut with band saw


remaining part


this is the connection hose needed, 5/16 inner diameter, get the vacuum hose, not the fuel hose 2 foot is plenty long


need some hose clamps, I'll use these for now and replace them with quick connects


get abunch of these elbow connectors at 5/16 in 5/16 out. since these are Tee's need to cap off one end, just melt it shut or epoxy closed

mix equal part resin and accelerator


glue end with epoxy and jam into nozzle inlet hole, let cure. position elbow connector like so


attach 5/16 hose to air horn as shown to direct compressed air toward OEM horn location when mounted


should look like this


attach electrical attach panel into left knee cavity


nozzle fits on the interior of the horn cavity



remove OEM horn, disconnect wiring


horn removed


the orientation that fits and allows drainage. There are only 2 angles that fit. This is not the best, but allows drainage if water ingresses into the horn. allows outer cover to be removed. Zip tie into position.


running hose from nozzle back to horn compressor for attachment.


compressor in knee cavity


zip tied nozzle



Results:
I enjoy the piece of mind the loud horn provides. I believe a must for all 2 wheel riders.
Enjoy and all the best!
Keithm
Couple extra shots as an FYI....


dielectric grease


wire crimper tool, don't use plyers


10 gage wire spool


properly made female spade connected to 10 gage wire


relay instructions


close-up of my wire connections


using a heat gun to shrink spade connector

nice job, thanks for the great pics as well.

I have seen others attach the horn nozzle into the fwd horn cavity in a more upright position. This is a re-orientation attempt. The intent is to rotate the nozzle part of the horn 90 degrees clock-wise. This will eliminate a elbow air connector in the compressor path. Some trimming will be req'd.


horn as is sits (zip tied) to the steering stem. I un-zip tied the nozzle, removed the hose and fiddled with the position. The nozzle would not fit unless some trimming took place.


trim this un-needed bracket, I used a Dremel cutter bit


removed flange. Only need one side removed as the horn interferes with the left side of bike. right and left side is always from the orientation of the operator sitting on bike


try fit again, need to trim horn abit


cut these parts here


drill hole for zip tie attachment


fit check after trim


zip tie to steering stem and lower bracket


re-attach air hose


view of lower zip tie and aux light wire

horn as seen thru panel grate.

Observations:
1. no noticeable difference in sound pressure level
2. The mod removes a elbow joint
3. no water ingress into horn, orientation allows drainage (as did previous location)
Enjoy!
Keithm

Here is a source for 5/16 elbow connectors:

SALES@ADVANCEDFLUIDSOLUTIONS.CO.UK
or
E-bay link
http://www.ebay.com/itm/260463536681?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
keithm