Question for 2 stroke fans......

Shouted the 500 triple an "Ivans Jet Kit".
As most triple owners know the carbs for these are pretty simple and not much can go wrong.
But....
I have one troublesome carb that no matter which cylinder I put it on,it doesn't fire and the corresponding header pipe is cold.
So therefore have taken electrickery out of the equation.
The carb in question is super clean and float has been set to the correct level @ 25mm.
Struggling to come to grips with this problem and have no answers.
Any help would be appreciated .....
As most triple owners know the carbs for these are pretty simple and not much can go wrong.
But....
I have one troublesome carb that no matter which cylinder I put it on,it doesn't fire and the corresponding header pipe is cold.

So therefore have taken electrickery out of the equation.
The carb in question is super clean and float has been set to the correct level @ 25mm.
Struggling to come to grips with this problem and have no answers.
Any help would be appreciated .....
