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R1100RSL Carbon Canister Removal and Airhorn Installation

Carbon Canister Removal and Airhorn Installation on a 1995 R1100RSL

by Gary Wasserman

Background: Having recently come to the conclusion that the carbon canister on my RS had outlived it’s usefulness (presuming it had a period in which it absorbed fuel vapors and delivered them for burning in the engine) I decided to remove it. I consulted Ian at ABMW and, of course, the net for advice. Ian concurred that removal was a good idea. Speaking hypothetically he outlined a likely course of action. A few R11 list folk suggested some of the things Ian mentioned but nothing more.

While at ABMW I procured the parts, two rubber caps to seal the nipples on the throttle bodies. I planned to spend a few hours over the weekend removing the canister. The cost of these caps, used on K-bikes, was, lets say, extremely low.

I have long planned three other modifications which for lack of time I have never done. The mods are: a horn upgrade, a brighter headlight bulb, and installation of my old Priority Plus box. In the interest of time (surprise) I passed on the Priority Plus box but decided to do the horn and bulb in addition to the cannisterectomy. Some may argue that a Priority Plus is a breeze to install but my answer is, “not if you are soldering pigtails.”

I read Rob Lentini’s article on a “Sanitary” dual horn installation, wrote down his bolt and spacer recommendations and headed out to the auto parts store to buy the “Fiamm” plug compatible dual horns.

Marc, my seven year old son, came along and while I was comparing decibel ratings and prices on the available snail-shell horns he was busy looking at and asking questions about the air horn kits hanging on the same rack. I finally paid attention and started looking at them myself. I picked out a Hella dual horn kit that looked pretty slick. Dean Cookson, list master for the NEDoD, had installed dual air horns on his VFR750 years ago to good effect so why not put them on the R11?

Dual Fiamms cost about $9.00 ea. The knock-off snail-shell horns cost about $5.00 ea. The Hella Twin-Tone Compressor Horn kit cost $32.00. But it made me smile (see also M. Golding). I bit.

I also picked up a 80/100W H-4 replacement bulb (about $10), wire and crimp-on connectors. Then it was over to Radio Shack for an in-line fuse holder and some 25A quick blow fuses. The whole list of parts needed for the airhorn installation is below.

Disclaimer: What do I know? Hey, I’m just a motorcycle owner like you. I listen to the chatter on the net, talk to my mechanic, and use my judgment to decide what I want to do. I suggest you do the same. If you are in any way uncomfortable with performing mechanical work on your motorcycle don’t do any of this. As far as I know everything I’m writing is wrong. Put another way, my advice is worth exactly what you paid for it. Proceed at your own risk!


Tools: You need a 10mm box wrench, a 5mm Allen wrench, a utility knife that is very sharp, and a Philips screwdriver. If your hoses are very stubborn a small pliers for grabbing the hoses may help. I was able to disassemble the hose connections by hand. The older the rubber the tougher this may be. Also helpful are a small mirror and a flashlight.

The canister is the black tin can attached to the subframe rail at the rear right of your bike. The plumbing is depicted in Figure 1. I’ll refer to the labels in Figure 1. in the following description. Thanks to Ian at ABMW for the original schematic drawing.

Bike on center stand. Remove right side fairing. You’ll need to do this to gain access to the rubber hoses. If you have bags on the bike take off the right side bag. Remove the left side fairing. You need to do this to gain access to the solenoid and associated plumbing.

Pull off the three hoses that connect to the front edge of the canister. The front of the can is held by a clamp attached to the passenger footpeg frame loop. Remove the bolt and clamp with a 5mm Allen wrench and a 10mm box wrench or socket wrench (the bolt is invisible behind the clamp; this is where the mirror is handy). Once the nut is off squeeze the clamp to release the bolt disconnecting the clamp and can. Save the clamp and bolt for the airhorn project (below).

Remove the can from the bike by sliding it back parallel to the frame rail. It will unhook from the metal tab and come loose. Donate it to the BMW parts museum (you don’t have one of these?).

The plumbing removal/modification is the next step. First work on Tube A. Locate the solenoid (my bike is a ’95) on the left side rear of the air box. It’s a weird little gizmo that has it’s own rubber mounting device. It is just ahead of the side panel extending from the tail section. There is one of those slick spring locked electrical connectors running to it. Leave the solenoid and it’s electrical connector on the bike; Brian at ABMW thinks this is cleaner because there is no dangling electric connector to deal with. I agree.

Pull the hose off the forward side of the solenoid and follow it over to the “T” where it splits. One side of the “T” goes down (B) to the left throttle body. Disconnect the “T” from all three hoses.

Remove the left throttle body hose and discard. Immediately cap the nipple on the throttle body.

Go to the right throttle body and remove the hose from the corresponding nipple (C). Cap immediately. Gently pull the hose through from the right side and discard. On the right side free the hose back to the solenoid (it runs in some clips) and discard.

The hose from the rear of the solenoid (D) is a pain. I gently pried the side panel away from the bike to gain access to the hose but I couldn’t free it from the connection to the solenoid. I decided to cut it at the bracket just behind the solenoid using my utility knife. For Gods sake be careful! Once the hose was cut I traced it back behind the fuse box where it was clipped gently freeing it as I went. I then pulled it out of the bike and discarded it. BTW if you have an old car with rotten vacuum lines you could use the old hose for patches. Just a thought.

Here is the slick part of the removal. Following hose (E) one finds that it is routed down to the bottom of the bike behind the rider footpeg plate. Here it lies alongside tube (H) and the battery overflow tube. DO NOT REMOVE THIS TUBE. Note there is a white plastic clip holding two tubes together. These are tubes (E) and (H). Remove this clip and keep it handy.

Follow tube (G) up along the frame to where it ends at a “butt” connector. The tube on the other side of the connector continues up to the gas tank. At the same spot there should be a butt connector tying tube (H) to a similar tube heading up the gas tank.

Carefully pull tube (G) off the butt connector. Discard it. Take tube (E) and lay it next to the butt connector. It will need to be trimmed to the correct length. Cut it and connect it to the butt connector. Now reinstall the tube clip you removed so that it ties the two “downtubes” together.

Viola. You are done. Stop and admire the marked improvement… 🙂

Air Horn Installation

My bike is an RSL. I doubt this installation has any applicability to the RSA model. However an industrious RSA owner might find a way to put air horns on his/her bike. I’d love to hear about it.

Tools Needed: Keep all the stuff you have out for the cannisterectomy and add a wire stripper and crimping tool, a 3mm Allen wrench, a 1/4″ socket drive, 6 inch extension bar, and 13mm six point socket. Also handy is a pair of snips (for cutting off the tails of cable ties and cutting shrink wrap) and a blade screwdriver. A heat gun or hairblower is needed for shrink tubing. An electric drill and assorted HS bits are handy for enlarging the mounting hole on the Hella relay.

Since you have the fairing panels off you have done half the prep work. Now remove the right side dash panel and then the left side dash panel. There are instruction for doing this in your owner’s manual under “changing the headlight bulb” or “changing the turn signal bulb”. Those directions are correct.

Overview: The compressor mounts to the original horn strap up between the fork tubes under the steering head. The twin horns mount on the left side. One uses the bolt holding the air intake “horn” to the frame. The other mounts ahead of it and uses the carbon canister clamp to hold it firmly but gently to the wiring harness. The original horn circuit including the stock relay are used to switch the heavy duty 30A relay needed for the compressor. A new line is pulled from the battery positive, fused and connected to the new relay. The horns weigh next to nothing and do not tax their mounting points at all. Note that the canister clamp has a rubber “bushing” (a strip actually) that was meant to prevent scratching of the footpeg frame loop. Keep this rubber; it offers an extra measure of protection for the wire harness.

You want to disconnect the battery for this job so that there are no nasty surprises while wiring up the compressor. You’ll need to tap off the positive terminal anyway (which requires removing the battery) so just do this first and face the fact that you’ll be resetting your clock. 🙂 The instructions for battery removal are in the users manual. They are correct. An extra pair of hands is great for that awkward moment when unbolting the positive side of the battery.

Details: Locate the original horn between the fork tubes at the top of the steering head subframe. One bolt holds the horn and a cable guide in place.

Remove the original horn. This is awkward but the socket extension makes it straightforward. Note the green wire is positive (switched) and the brown is ground (unswitched). Be nice to the spade connectors and wires; you’ll need them soon.

We’re going to recycle the horn mounting strap (actually it’s a stack of three thin straps). Note that the strap holding the horn is positioned behind the cable guide. They share the mounting bolt. Carefully observe how they fit together so that you can restore the original configuration after performing the task below. Unbolt the horn from the strap and save the horn along with the bolt and the washer (note the frequency on the washer).

Push the head of the mounting bolt supplied with the horn kit into the slot on the compressor. Push the bolt thread through the mounting strap hole (the one that previously held the round stock horn). Put the split ring washer and nut on the thread and tighten. Use some locktite.

Reassemble the cable guide and horn strap and rebolt to the mounting point.

Next mount the air horns to the left side. All the stock mounting hardware that comes with the air horns is used. This is comprised of a square head bolt that slides into a sleeve on the horn. A nut secures a bent bracket to the bolt. The brackets have to be rotated 90 degrees w/r/to the horn. The first horn has the bracket going down and back. Unbolt the air intake horn being careful not to bind or stress the fast idle cable nearby. Put the bolt through the horn bracket and reinstall. The air input nipple should be facing out.

Mount the second horn just ahead of the first by carefully putting the carbon canister clamp around the thickest part of the wrapped wire bundle. Put the clamp bolt through the horn bracket and then insert it through the clamp holes and secure with the bolt. Again make sure the air input nipple is facing out (see photo).

The horns should tilt slightly down to drain better (see next photo). I’m not sure what the optimal angle is but it is not possible to get much tilt given the mount points and available space.

Now connect the air hoses. The supplied clear tubing is adequate for the installation. NOTE: To get the best result make the run from the compressor nipple to the supplied splitter very short (approx. 2″). Connect the splitter to the short hose and then connect the hose to the compressor. Now attach the remaining hose to one side of the splitter and route the hose over to the rearmost horn. Cut the hose and attach to the horn. Lay the remaining hose alongside the first run and cut to approximately the same length. This will be more hose than needed to reach the front horn. However by keeping the hoses the same length you ensure that the horns will fire together and at about the same volume. At least that’s my theory.

Connect the second hose to the splitter and then to the front horn.

Now you have the compressor mounted, the horns mounted and the air line hooked up. Time to do some electrical wiring.

Crimp a stud ring (you female R11 owners take note) onto the red wire you purchased (see parts list below). Using the bolt that secures the positive cable to the battery temporarily attach the stud ring to the cable. Safety Issue: Note that the battery is unattached at this point. Move the cable end to the approx. normal position (ie the position it would be in when attached to the battery). Route the red wire under the tank towards the front of the bike. Use cable ties to secure. This is not easy since the clearance under the tank is limited. But I figure if my fat fingers can do it most people will be able to escape the dread tank removal procedure.

Bring the red wire up to the fairing support bracket to the right of the headlamp assembly. There is a nylok nut and washer there which appears to secure the headlamp assembly. Leave a few inches of slack and cut the wire. Crimp on a female disconnect (great name for a widget, eh? :).

Take the black wire and crimp on another stud ring (stud rings and female disconnects…it’s weird). On the left side of the motorcycle just above the rearmost horn there is a Philips head sheet metal screw securing two ground wires to the frame. Remove carefully and insert screw through new ring and reinstall so as to secure the new ring and two original rings. Tighten. This is the compressor ground.

Route black wire back up to the compressor left (motorcycle left) bottom where the ground spade connector is located. Cut and crimp on a female disconnect. Before installing on the compressor be sure slip a 1.5″ piece of suitable size shrink tubing over the disconnect and up the wire. Now install the wire on the compressor, slip the shrink tubing in place, and apply hot air. Don’t overheat.

Attach the hot lead from the battery to the inline fuse holder using a butt connector. Install shrink tubing before crimping. Crimp a disconnect on the other fuse holder lead and secure the fuse holder to the fairing support bar to the outside of the nut and washer mentioned above.

Attach the fused hot lead to the Hella relay terminal (see schematic) #30. Slip shrink tubing over the green and brown leads from the original horn wires and attach the green lead to terminal #86 and the brown to #85. I suggest preserving the original horn leads as is in case you ever desire to reverse the installation.

Fabricate a short wire from relay terminal #87 over to the compressor hot lead. Crimp on the appropriate connectors and shrink wrap them after installing them on the appropriate spade connectors.

Take the short (3″) piece of perforated metal strapping and secure the relay to one end with one of the bolts and nuts supplied by Hella. You will have to enlarge the mounting hole on the relay. Mount the other end of the strapping to the thread on the headlamp mount by removing the nylok nut and then reinstalling it along with another washer to secure the strapping. The strapping lowers the relay so that it is out of the way of the RID unit. What? You don’t have an RID unit??? OK. Eliminate the strapping and mount the relay directly to the thread.

You haven’t installed a fuse in the fuse holder, right? GOOD! Don’t do that yet. You have now got the basic wiring complete. Recheck all the connections and convince yourself the crimpings are good. Secure all wires against frame tubes or existing wiring/plumbing being careful to avoid the forks, the A-arm, etc.. When in doubt move the fork back and forth and put in extra cable ties.

Note that the compressor sticks down and back toward the strut. If you have lots of money and have installed the Ohlins shock you may have clearance problems. The stocker is not a problem. I bent the horn mounting strap slightly to angle the compressor away from the strut. What I found was that on the center stand this looks worse than it is. On the road the two never came close.

Reinstall the battery and be sure to put the stud ring on the compressor hot lead onto the battery post (thread the bolt through it before securing the nut). I suggest using the outside edge (behind the washer) and angling the base of the stud post forward to reduce stress on the crimp. You didn’t forget to shrink wrap that one, did you? Good!

Reassemble the air intake horn (you’ll have to remove and remount the rear horn), install the air filter and reinstall the air filter cover, etc.. Before attaching the ground cable to the battery reinspect the new wiring one more time. Don’t forget to reconnect the overflow hose to the battery and don’t forget the retaining strap! Now reattach the ground. No smoke? Good. Tighten the cable.

Install the 25A fast blow fuse in the fuse holder. I used a blade type fuse holder so that I could carry a spare in the fuse box. They are green and not easily confused with the nice blue and red ones used in our bikes. No smoke?? VERY GOOD! Now comes the real test.

Turn on the ignition and press the horn button. Try two toots to verify that you are getting fast reliable response. With the ignition still on recheck the wiring one last time and verify that there is no smoke or burning smell.

Shut off the ignition. Reinstall the fairing and dash panels.

Congrats. You are now a rolling acoustic menace. Even the most hearing challenged braindead cager in the most acoustically padded upscale cage will hear you now.

Remember, the horn is a means of communication not an insurance policy. Don’t count on it. Take an MSF course, wear protective gear (ear plugs are now a very good idea, too), ride aware, and never mix drugs, alcohol and riding.



PS – Please send me any corrections and/or additions so that I may continuously improve these directions.

Parts Lists

Canisterectomy Parts:

  1. Rubber nipple cap, K-bike part, part number unknown, Qty 2

Air Horn Installation Parts:

  1. Hella Twin-Tone Compressor Horn Kit 3PB 003 001-791
  2. Blade-Type Auto Inline Fuseholder – Radio Shack 270-1213
  3. 25-AMP Automotive Fast Acting Fuses 32Volt ATC blade type – Radio Shack 270-????
  4. 14 AWG stranded single conductor automotive type wire, red/black
  5. 16-14 AWG 1/4″ STUD RING
  6. 16-14 AWG Female Disconnect
  7. Assorted shrink tubing
  8. 15mm washer

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