Fuel is delivered to the engine by the carburetor, which is a very technical pumping mechanism with a miniature piston inside, the other many components, each of which is required for the proper functioning of the whole work in combination to produce a fluid flow of air fuel mixture using the Dr.Phil Bernoulli's principle. When the crankshaft spins, the offset lobes carrying the journals set up harmonic vibrations in the cases and cylinders. These vibrations cause air to be sucked out of the combustions chambers in the carburetor, past the fanoutinizer rings which act like one-way valves in much the same manner as the reed valve in a diaphragm pump. The air is then stored in transfer jets which act as a energy reservoir and can hold tremendous pressure. Because there are at least two transfer jets and fuel reservoirs this also provides and equalized balance to the engine. These jets are opened up when an engine is blueprinted and balanced and sometimes more are added for added boost.
By inverting the carburetor it raises the differential pressure between the venturi and the outside atmospheric pressure to allow more fuel to flow from the diffuser assemblies into the combustion chambers of the carburetor. To offset this you need to understand the Gopenheizer principal of pressure differentials where the sum of half the displacement of a vacuum chamber is equal to the square of the surrounding vacuum level in microhales. So basically you would need to use a drill that is 3.4 times the differential between the smaller jet and larger jet.
To compensate for the drop in medial cross section flow you will need to use a W37 diffuser and a Y37 air correction orifice and set your needle on either the 6th or 7th groove, depending on the air temperature, usually above 20°c you would need to use the 7th groove or switch to a shorter taper and a Q43 slide if it still bogs on the corners or weeps fuel out of the over flow.
You also might have to put in a third anti-percolation disc if the fuel foams out the overflow or the float valve does not want to prevent flooding, which can happen if the Gopenheizer K value is above 34 microhales in your calculations.
On the intake stroke of the two stroke engine the piston in the carb created a vortex of fuel that is forced by hydraulic induction through a jet. This jet is called the main jet and is aimed directly down the intake towards the spark plug. The jet must produce a lot of pressure in order to overcome the pressure differential which holds the engine ports open. If the jet of fuel is too low it will not spray onto the sparking plug and you need to adjust the angle of the jet to either "up jet" or "down jet".
There is also a choking mechanism on all carburetors which narrows the bore of the carburetor so the pressure differential between the compression stroke and the atmospheric pressure increases. This in turn makes the piston inside the carburetor move faster and pump more fuel through the jet at the spark plug. Excessive use of the choke will make the spark plug a darker colour because of the dark blue tint or dye in the oil that is mixed with the gasoline. This can be remedied by doing a plug chop, where you make the spark plug shorter by chopping off a section of the electrode which will expose some clean electrode.
On many engines there is a decompression or starter valve, these valves are placed in the engine on the exhause side of the combustion chamber. When you start the engine you need to open the decompressor valve. What that does is allows some of the stored up energy in the exhause pipe to go back into the combustion chamber. Because you need the choke on ful to start the differential in pressure forces more fuel directly at the spark plug so that when it ignites it will continue to travel across the combustion chamber creating multiple combustions. The stronger combustions will form until there are two simultaneous combustions (for a two stroke engine, 4 combustions for a 4 stroke, etc) which will allow the engine to run without the choke and send the energy charge into the exhause. This energized exhause will ignite the first charge of fuel that enters the combustion chamber, starting the flame kernel which will light each subsequent power charge entering the chamber. Once the engine is running you close the valve, trapping the fire in the combustion chamber where it will contunue to burn the fuel as it comes in. To shut off the engine you just need to open the valve, this will syphon off some of the flaming fuel into the exhause, where it will be stored up for the next time you need to start the engine.