Trigger warning, LOL. This isn't a slick video. It's a start to end (with some gaps) of how I did the mod to a gen 3 MT09 exhaust.

It was constructed over 4 separate days and my focus was on the mod and not the filming.

You can hear the outcome here    • Yamaha MT 09 SP Gen 3 exhaust stock v...  

This was done using tools I mostly already had and without cutting the outer shell of the stock exhaust. The total outlay was less than $300 AUD for the spare exhaust and consumables plus extra for some tools that will last me for decades.

I also set out to make it in a way that would allow me to pull it apart and modify it without a huge amount of effort. That's why the main parts are riveted together and not welded.

I don't feel that it was necessary to make it be able to be disassembled though. I did that as a precaution.

Now that it's done I feel that this is a mod that could be done properly by an exhaust fabricator pretty cheaply and given how successful the outcome I may re-make some of the components and get parts of it welded for a more professional finish... except that would mean removing the exhaust again...

Yamaha did not make that easy which is a surprise. There's no room to get to half of the bolts without removing the radiator and even the kickstand switch is in the way of one of the bolts.