bike bogs uphill and on flat after 5 mins of driving

another problem -_- ive changen the manifold that had a split in it but still its going really slow uphill and if i try to give it more throttle it bogs :/ same on flats. today i was driving for 5 mins when suddenly it started bogging to 60 km/h when it normally does 80+ but then soon as i get to a slight downhill its absolutely fine. it has a 70cc engine , 21mm carb , 72 main jet (smaller jets are a 50 and 60) sport air filter , sport pipe and 5g rollers. it was fine till i upgraded to the bigger carb and had to put a different petrol tap at the bottom of the tank on coz it doesnt have a blower on the carb to make the petrol go through. thanks

 

thats wat it has been changed too

 

i think jetting is your problem mate buy a jet box

 

okok my mate has quite a few jets for it so ill try them thanks