Hello I have a keeway f act 50 scooter and it only runs when mixture screw completely turned in and then not 100 % because it has a gas/acceleration hole if I have a basic setting i.e. 1.5 revolutions back runs it in the stand as soon as I give gas it goes out of membrane I have renewed carburettor cleaned petrol comes of the further I have a problem if mixture screw is completely turned in it accelerates from 0-20 normal from 20-40 he has a huge gas hole saying there is hardly anything or ultra tough and then from 40-60 it pulls through clean again can someone help me? LG Sascha