First of all i think i know how to do it just need someone to confirm, my bike wont tick over cold and it runs better when its cold and wet weather and as air is thicker when its cold im putting it down to the pilot screw and maybe jet, and it will only go to 60mph then bog and wont go any faster even though theres some more revs for her to give i know the main jet mainly controls the fuel flow when the throttles at 3/4 - full so im guessing thats were it goes wrong up jetting will be needed ill do this because im waiting for the mot in july before i put a 170 kit on it just thought idd share this for anyone else and also so people can confirm im right

Fundamentally correct.

You may have an air leak. When did you last change/clean/oil (if appropriate) the air filter?

I havent got round to changing the oil yet and i got a airfilter and spark plug when i got it in december