Author Topic: Split Stebel Installation on ST with ABS ( ST1100 )  (Read 6291 times)

Offline KoTAOW

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Split Stebel Installation on ST with ABS ( ST1100 )
« on: April 16, 2009, 06:39:55 AM »
Split Stebel Horn Installation on ST with ABS
written by Phil Derryberry, STOC # 698

NOTE:  Left click on picture to go to Webshots and view higher resolution.


The available space under the body work of a ST1100 ABS makes the installation of the
Nautilus Compact Stebel horn a real challenge. This install takes you step by step on
how to separate the compressor from the trumpet for a more flexible installation. It also
allows you to place the trumpet at the front of the bike as it should be and the
compressor in a nice dry spot so water has much less chance of getting inside it and
causing damage. First, here are pictures of most of the supplies that you will need for
this project –


One Stebel Nautilus Compact Horn

One 5/16” Plastic Nipple

Two 5/16” Fuel Line Clamps

Two Feet of 5/16” Fuel Line

Six Inches of 1/8” thick, 1 ¼” Strap

30 AMP relay (not the one with the horn)

Two 2/14 inch Hose Clamps

Various Wire and Terminals
(described below)

The wires and terminals you will need are (lengths are approximate because it depends
on where you put the electrical components) :

Three feet of 18 gauge wire (red), eight feet of 12 gauge wire (red), three feet of 12
gauge wire(black), four right angle terminals (for relay), 3 ‘eye’ terminals (1 for ground
for horn, 1 for ground for relay, 1 for battery or fuse block connection), 3 female spade
terminals (1 for hot to compressor, 1 for ground to compressor, 1 for terminal on stock
horn), and 1 male spade terminal (for pigtail to original horn connector).

Special tools needed are a drill bit that makes a big enough hole that you can get a
12mm socket through, a vise and really good hammer for making the compressor
mounting bracket.
« Last Edit: April 16, 2009, 02:33:30 PM by KoTAOW »

Offline KoTAOW

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Re: Split Stebel Installation on ST with ABS ( ST1100 )
« Reply #1 on: April 16, 2009, 08:28:03 AM »
Step-by-step procedure:

1. The first challenge is to separate the trumpet from the compressor. There are two
places that must be gently pried loose to accomplish this. The first one is at
plastic cover that is the original air intake. Gently insert a screw driver and pry
upward to free this part.

The next place is near the front where the compressor plugs into the trumpet. It is a very
‘fragile’ loop that probably would not be a problem if it broke off. But it is handy to tiewrap
the nozzle to that you will need later.

With gentle pressure at both places, slide the compressor out of the trumpet

2. The next step is the point of ‘No Return’. With a Dremel tool or a carefully
wielded saw, cut the ‘ears’ off the trumpet that cradled the compressor. This
makes installing the trumpet a lot easier by reducing the space needed.

3. Install the 5/16” nipple in the hole in the trumpet that the compressor was
plugged into. Use a plastic tie-wrap to secure the nipple wrapping it around the
very ‘fragile’ loop you were not supposed to break off. If you did break it off,
improvise so that the air pressure does not blow the nipple out of the hole.

4. Cut about 6 inches off of the 1/8” thick by 1 ¼” wide strap. Mark a line (Sharpies
work nicely) at 3 3/4 inches, then another line about 3 /4 inch further. These are
the rough bend lines you will need.

I put the piece in my vise then vigorously beat it into submission. The result when you
are finished should look something like this –

Drill a hole for the bolt to go through (back bolt of the upper motor mount) and a bigger
hole that the head of the bolt and a 12mm socket can be inserted through. The small
hole is drilled about ½ inch in on the short leg. Let the bit drill straight through to the
longer leg. This gives you a pilot hole for drilling the larger hole and insures alignment

5. Paint the bracket with something like Rustoleum paint. You will need to remove
the right fairing pocket so you work in the area. Put the bolt back through the
bracket and tighten to whatever torque specs you can find. The position of the
bracket may need to be adjusted so have a 12 mm open end wrench handy

6. Slide the large hose clamps onto the bracket and slide the compressor into the
hose clamps. The air outlet should be the outside of the bike. I recommend that
the tightening screws for the big clamps be placed between the legs of the
bracket to conserve space. Slide the compressor as far back as you can (almost
touching the bodywork brace). Tighten the large clamps snuggly so that the
compressor cannot move. The inlet hole for the compressor should be facing
upward, which keeps water from easily splashing into it. The below view is from
the top looking down. The positive electrical terminal will be next to the engine
and the ground electrical terminal will be to the outside.

7. Next, installed the 5/16” fuel line hose onto the nipple in the trumpet and secure
it with the fuel clamp. Is it much easier to work the fuel line back to the
compressor than it is to try to install the hose on the trumpet and tighten the
screw after the trumpet is in place – trust me!

8. Then carefully (takes much patience), put the trumpet into the space between
the outer fairing and the inner fairing near the radiator on the right side. This
takes a bit of maneuvering to accomplish but it will eventually drop right into this
space, and rest on the carb air hose intake nozzle. The hose should be point to
the back of the bike toward the compressor and has to be working through the
maze of wires and hoses. You can just barely see the edge of the trumpet in this
picture. Right above the location of the trumpet is a nice brace that you can run
some plastic tie-wraps around to secure the trumpet in place if you feel the need.
You will need more patience and extra long tie-wraps to accomplish this.

9. Slide the fuel line clamp on the other end of the hose once you have fed it back
toward the compressor positioning the screw on the clamp so you can tighten it,
then work the hose into the compressor nipple and tighten the clamp. That takes
care of all of the plumbing. Now on to the electrical.

10. Take the 18 gauge red wire and make a ‘pigtail’ for connecting to the existing
horn switch circuit. The male spade connector fits into the ‘hot’ wire that was
plugged into one of the existing horn terminals and will have a very short piece of
wire to connect it to the female spade connector. From the female spade
connector, you will need the length of wire to reach the new horn relay wherever
you decide to put it. I usually put them under the front cowl on top of the
headlight so they are out of the weather but easy enough to get to by removing
the windshield and the garnish. The key is making sure you pick the correct ‘hot’
wire that is connected to the existing horn. From the back of the bike, it is usually
the one on the left. An easy test is to check it with a simple test light while
pressing the horn button with the ignition key on. The female spade connector
will plug onto the terminal of the existing horn that you removed the ‘hot’ wire
from. This setup allows the stock horn to still function and will be the switch wire
for the relay to the Stebel horn. Just a hint – if you remove the left fairing pocket,
hooking into the original horn wiring is a lot easier since you can see what you
are doing then.

11. The wiring to the relay is quite simple. The relay (a 30 amp model) has 5 prongs
with numbers on them. The 18 gauge red wire from the switch pigtail goes on
terminal 85. The 12 gauge red wire from the power source (either the battery or a
fuse block – if the battery, you will need to put an inline fuse in the wire), goes to
terminal 30. The 12 gauge red wire to the compressor goes to terminal 87 (there
is also an 87A terminal which would work also). The 12 gauge black wire which
should be connected to a ground point on the bike goes to terminal 86. Here is a
diagram that might help. You will also need to run a 12 gauge black wire to the
ground terminal on the compressor and a good ground spot on the bike.

Once you complete the wiring, you should be able to test it with the ignition key on.
Then comes the toughest part of the install – getting the right fairing pocket back in and
getting the external air carb hose routed so it all fits. You could probably remove this air
hose and do no harm (a STer I know has run his for years without one), but if you are
not comfortable in doing this, prepare for a bit of a struggle. The compressor now sits in
the direct path of where the hose used to run. I stretched my hose out a little bit,
mashed it a little bit, then routed up and over the compressor. You will also have to be a
bit careful where you route the fuel line from the compressor to the trumpet or you may
have trouble getting the maintenance cover back in position. No easy shortcuts here,
just fit a nice comfortable seat to work from and fiddle with it. It will all go back together
but not without a struggle. Good luck with your install and many happy toots! However,
no warranty is expressed or implied in this document … ;-)

Phil Derryberry (Uncle Phil) can be emailed at
« Last Edit: April 16, 2009, 02:33:47 PM by KoTAOW »