When I first posted this thread I had just picked the bike up and it needed work to get it to stage "0" before I began tuning.
The bike is now on the road and hits around 28/29mph on the flat and is completely standard, the spark plug is a little darker than spot on but I don't mind running a little rich.
I now believe I am ready to start tuning.
Ordering an exhaust from treats would be great but I can't justify the shipping costs and customs fees associated. So I am going to have to make my own exhaust.
I have got an exhaust from a 2 stroke pocket bike which looks to have an ideal size expansion chamber for my machine, as well as pipe bores, so this is where I will start from. Still looking in to carb options.
What is the realistic top speed people have seen out of there NX/NU50? I rode my friends 2015 Aprillia SR50 last night and the acceleration is immense compared to my NX, with a top speed of around 50mph!