Triumph Bonneville Main Jet Swap without removing carbs

This is a quick post illustrating how to change the main jets without having to remove the full carburetor assembly. Being able to swap jets quickly is crucial when modifying your bike and this saves you the pain of pulling half the bike apart.

First, unscrew the four bolts holding the float bowl in place with a small hex key. Make sure to drain the bowl before hand!

With the bowls removed, you can easily see the diffuser and main jet sticking out past the float.

Use an 8mm wrench to unscrew the diffuser. Be aware of the small collar that sits on top of the diffuser. As you are removing the diffuser it may fall out so keep an eye out for it.

Now you can swap the main jet.

And in the timeless words of every workshop manual, "Installation is the reverse of removal."