Thanks bob very interesting I will have to have a look at my carbs (I have a few) to see what jets they have.....To hop up a full crank for a gokart top of the list for carbs would be a Mikuni but they do cost big bucks but you can buy any jets you like sky's the limit with a Mikuni, It dont matter how far you want to go even 2in flames out the exhaust! it would be a walk in the park for a Mikuni carby haha....