why is my speedmaster still popping?

I have an 04 plate speedmaster that has always popped on deceleration.

I did have tors on the bike until recently, when I switched to a set of trident exhausts. The reason for the switch is I wanted something a little louder than the tors, but not too excessive. I like the raspier sound of the trident pipes.

Anyway, I purchased an air injection removal kit, but after reading the instructions and watching a YouTube video, I realise that my bike has already had the injection kit removed...doh!

So, why is my bike still popping so badly? I have taken it to a garage who put it on a rolling road and said its running fine. But personally I would prefer it not to pop.

I think it must have been rejected at some point as the original screws on the carb have been replaced with Allen bolts.

I know nothing about mechanics..so I am a little stumped, especially as the garage said its fine.

Any ideas? Or anyone know of a garage in somerset that can look and possibly rejet?

 

Apologies....just realised I should have posted this in the speedmaster/america forum...

But any replies appreciated...especially on recommendations for a garage or tuning specialist in the mid somerset area.

Thanks

 

Apologies....just realised I should have posted this in the speedmaster/america forum...

But any replies appreciated...especially on recommendations for a garage or tuning specialist in the mid somerset area.

Thanks