Test ride done! I did have to reset my idle speed it was at around 1500 to 1700 even with the engine warm.
Observations:
1. Much more responsive with the throttle.
2. Smoother taking off, and seems quicker taking off. Definitely faster.
3. No exhaust backfire after letting off the throttle and no carburetor backfire either.
4. Somehow the gears seem longer. This kind of related to point 2.
5. Sound is definitely nicer. Before it seemed a bit loud without purpose.
6. It was even more fun to ride and it was fun before.
Conclusion: On the carburetor model of the Thruxton, removing the airbox, removing AI, installing free flow (performance) mufflers and upgrading jets is a good recommendation. If the motorcycle has already had one or more of these mods done it makes even more sense. I had a nagging feeling something was out of tune or not exactly right with my Thruxton, but without someone more knowledgeable than myself putting eyeballs and ears in person to it I couldn’t confirm anything. My thought is that with the performance type exhaust installed and AI removed a 45 pilot jet was perhaps a size too large or keeping the main jet at 110 was too small. Not an expert, so can’t say that either was the reason for exhaust backfire when letting off the throttle, but I do think the jets supplied with the British Customs airbox removal kit are correct for a setup with the listed modifications. The key to this motorcycle is selecting the appropriate jets after any major components are removed or changed.
This has been an exercise in learning for me and learning a bit about this motorcycle. For some people these mods are not possible due to state and local laws and regulations, so know your local restrictions before getting started. I know this isn’t the way the Thruxton could’ve ever come out of the factory, but to me it is the way it should have been. Definitely has that old 60’s motorcycle vibe now, the ones I remember seeing as a kid. LoL.
