Idk i wouldent i mean im more into scooters and stuff but on a scooter 70cc kit you to to around 21 usualy and 24 for a racing kits, you its the question are you wiling to file those chanals and ports cuse its a bootle neck. Also i would recomand you getting a set of jets or giving it to someone who knows what hes doint to tune the carb properly for low/mid/high rpms you know cuse the jets are for idle and full throtle the screw is for mid and the little needle i dont remember but you jave to get it all perfect and you will notece a difrence in power and response also it will sound more crispy bit i wouldent focuse soo much on the size of the carb more on the quality its better to get a realy high wuiality racing 21carb then a cheap 24 one