RE: New mcd cy motor tuning trouble(gas tank)!
try;
put high speed needle to stock setting and leaning it out a touch (with exhuast off if its stock can)
check for airleaks in fuel lines
spray water around carb gasket and linkages (everywhere but down the carb) and listen for engine noises changing or use soapy water and look for air bubbles
check your fuel filter in the tank
all i can come up with for the moment
Ryan