Fuel- I had to Torque philp screws tight. Next step if it starts leaking is to replace phillip screws with allen head screws. And a small amount of fuel combatable perma-gasket on both carb halves till "tacky". Then use old gasket if it is whole and undamged. (perma-gasket will hold by itself) Then lightly torq screws for 24 hours. Then medium torq when dry. Lock washer is not a bad idea for Med torq on new gasket material.
Air leak- I bought the 9/16 O-ring from the auto parts store. The size matched the air tube from carb. The butts up to intake mount. I then sealed the four slits in the compression slits. This is for extra hold so the carb won't slip loose.
Good Luck man...I hope your float bowl is not flooding? Whole different kind'a leak fix!
Engines are good so far...Minor allen head upgrades for prevention of stripped screw heads with a screw driver. Important Head bolts should be replaced with higher grade steel. Fuel upgrade from tank petcock, Braided fuel line, and hose clamps will make for leak prevention.