Al Smith
Mac Daddy
It's not the amount of air available on the atmospheric side of the carb but rather the area of the intake channel.Theoretically say for simplicity sake of explaination say you had a 1" venturi connected to a half inch intake tunnel .It would only pass 1/4 of the amount of air were it a full 1 inch .Now that's an exageration but the point still remains .The only way you could get any more air through a smaller tube is by forced induction ,blower .You're dealing with atmospheric pressure .
Then enters into the mix the needle valve .That thing is only regulating the fixed jet in the carb .It's the pressure drop over the fixed jet and the size of it that determines the amount of fuel it will suck .That plus the fact that being a pulse carb it acts somewhat like a mechanical fuel injecter with the positive and negative pumping action of the diaphragm .
I don't know if this will work or not in this application .Often times a "ram tube " basically a funnel connected to the air intake of the carb can increase the air flow .It actually acts like a funnel but has no effect unless the engine is running at speed . They used them on go karts ,hot two cycle bikes ,snowmobiles and I have one on a 2100 Husqvarna .Still in all what effect that would have on an undersized intake I have not a clue .Might not do a thing .
Then enters into the mix the needle valve .That thing is only regulating the fixed jet in the carb .It's the pressure drop over the fixed jet and the size of it that determines the amount of fuel it will suck .That plus the fact that being a pulse carb it acts somewhat like a mechanical fuel injecter with the positive and negative pumping action of the diaphragm .
I don't know if this will work or not in this application .Often times a "ram tube " basically a funnel connected to the air intake of the carb can increase the air flow .It actually acts like a funnel but has no effect unless the engine is running at speed . They used them on go karts ,hot two cycle bikes ,snowmobiles and I have one on a 2100 Husqvarna .Still in all what effect that would have on an undersized intake I have not a clue .Might not do a thing .