how do i set up the fuel system in an rc airplane?

i just converted to nitro after a year of flying electric planes..ive done hours of research and now im stumped…how do i set up the fuel system from the engine to the tank and i heard of fuel going to the muffler or something and u need to buy something called a clunk any step by step instructions or a video would be great

On "pressurized" systems, which are MOST modern systems, the vent line goes to the pressure fitting on the muffler. There are NORMALLY only 2 lines from the tank. There may or may NOT be a fueling valve in the carb line. IF NOT, then the line would need to be detached from carb for fueling. A 3rd line for fueling CAN be used, IF it is securely plugged while running.

The "clunk" is in the tank on the feed line which goes to the carb.
When you buy a NEW tank, it includes the fittings, short tubing pieces, (metal and flex,) and "clunk", as well as directions on assembly.

Older systems used several different ways; electric pumps, crankcase pressure pumps; and older yet NO pump, (which depended on carb vaccum only.)