Today I installed the British Customs Airbox Removal Kit (A.R.K.) on my 2008 Triumph Bonneville. It basically required a full day. You should plan ahead and allow plenty of time to do this modification.

First I jacked up my Bonneville on a motorcycle jack and secured it with straps. I stripped it down by removing the seat, gas tank, exhaust pipes, rear brake and tire, side covers, and front chain cover.

First Steps

First Steps – strip down the Bonnie.

I followed the Instruction PDF file that I downloaded from the British Customs website.

Stripped down Bonnie

Stripped down Bonnie

After removing all the items attached to the OEM Airbox, I pulled it out (through where the back tire was). It’s basically a plastic box with two holes for the carbs, a hole for the air cleaner, and a place for the battery.

Triumph Bonneville OEM Airbox Assembly

Triumph Bonneville OEM Airbox Assembly Removed – with K&N Filter

I inserted the British Customs aluminum battery case in its place and remounted all the items that attach to it. I discovered that BC did not include the “hardware” for mounting the brake reservoir or fuse box to the new battery box, contrary to their instructions. Fortunately I had some bolts that fit.

My battery left a space about and inch and a half in front of the battery, which turned out to be a perfect place to store my Mosfet Rectifier/Regulator that I had purchased previously from RoadsterCycle.com. The OEM battery strap held everything snuggly in place.

Battery in Place

Battery in place with Mosfet Rectifier in front

BC Airbox Removal Kit

BC Airbox Removal Kit

Once I had the new box and all attachments mounted, I replaced the rear wheel, brake, and other items.

Attaching items to new battery box

Solenoid attached to new battery box

Next, I tackled the carburetor re-jetting process having never done it before. Here I am draining the carb bowls with a 3mm hex wrench.

Draining Carb Bowls

Draining Carb Bowls

The instructions said they were using 140 main, and 42 pilots. They shipped me 135 Mains, and 40 and 42 pilots. I didn’t know what to do and couldn’t get in touch with BC on the weekend, so I installed the 135/42 combination.

carburetor adjustments

Bonneville Carburetor Re-Jetting and Adjustments

A word to the wise that is not in the instructions. When you loosen the main jet (8mm) and let it fall from the bottom of the carb, watch out for a small brass fitting (jet) that will fall out with it. It would be very easy to miss this and lose it if you aren’t careful! Not having the best tools for this section really slowed me down. I had purchased a T3880107 Carb Adjuster Tool per the instructions, but it did not fit anything that I could find on the carb. You really need a short philips and flat blade screwdriver in an “L” angled shape for this. I ended up using an adapter on my 1/4″ ratchet to do this.

Bonneville Carbs

Draining the Bonneville Carbs

I also could not identify the idle mixture screws in Step 28. The BC photo is too dark, and the instructions were not clear, and neither was the Haynes manual. So, I had to skip this step.

Finally I had the carbs back together, and mounted the brace that comes with the kit. After replacing everything else that was still not attached, and the K&N filters and crankcase filter (which was missing the hose clamp described in the instructions) I started it up (and it did fire up!).

Side Covers Removed

View with Side Covers Removed

It was running rougher that normal, so I decided to get out the BC 2 Carb Synchronization kit I had also purchased. Following instructions I warmed up the engine and then attached the synchro gauges and hoses. They fluctuated so wildly while the engine was idling I could not use them for any kind of adjustments. So, after sending an email about this to BC, I was forced to abandon this final step as well.

I then took the bike for a test spin. I was underwhelmed with the initial experience. It did not feel any different than the way the bike was before. I will wait to see what can be done about the idle mixture screws and the carb synchronizer before I make a final judgement.

So, my initial installation and conversion experience was half satisfying and half frustrating. I like how the bike looks and sounds, but I was frustrated that I didn’t get all the parts that were described, and I couldn’t figure out their instructions at several points. Not being able to get in touch with anyone at BC on a weekend is annoying. Most people like me do these  installs and mods on the weekends.

Stay tuned.

Airbox Removal Kit Conversion Completed

Airbox Removal Kit Conversion Completed