Triumph Air Box Mod
I will not be the first to say that the engineers at Triumph did a great job designing my 2001 Bonneville but in typical engineer fashion they made it easy to assemble, not easy to repair. Case in point, the rubber boots connecting the carburetors to the air filter box are ridiculously hard to remove and even harder to reinstall. If you have ever needed to remove the carburetors you know what I am talking about. It’s easy to see that these boots are easy to install if the air box is on the bench and the boots are fitted on the air box before the side covers are screwed on. Then, without the back wheel blocking the path, the air box will slide straight into the frame and fit right on to the carbs. However, if all you want to do is take off the carbs to clean the jets or replace the float needles this is absolutely no help at all. So after fighting the rubber boots to get the carbs off for the third time I swore I would never do it again.
I like the contoured shape of the rubber boots, and the big air filter, so I decided to modify the air box instead of scrapping it. After some careful examination, I saw that a small removable section, on the air box side cover, would make it a lot easier to install the rubber boots. With that plan in mind, I set about removing the side covers. Of course I soon found out that some screws that hold the side covers in place are hidden behind some of the frame members. Thanks again to the Triumph engineers. Undeterred, I removed the battery and started removing the screws that hold the air box in place. I was happy to find that the box could be displaced just enough to remove the final screws and get the side covers off. With the side covers on the bench, I used a thin-blade coping saw to cut off a section around the boot hole. I made sure the section I cut off had three screw holes. I sanded the cut edges of the side covers smooth, spread silicon sealant on the flanges, screwed them back on to the air box, and then bolted the whole thing back into place.
After cleaning the jets and washing the dirt and corrosion out of the float bowls, I put the carbs back on the engine. At that point, it was easy to rotate the rubber boot about a quarter-turn outboard, push it on to the carburetor, and then press the boot’s flange into the air box opening. Once the boot’s flange is engaged in the air box, it was no problem to rotate the boot into the correct position. Finally, I laid a bead of silicon on the cut edge of the removable section before fitting it into place and screwing it down. Now I’m ready to run and happy to know I’ll never have to fight those rubber boots again.