Originally Posted by SpeedingTurtle
I don't know what that is. This is my first build. I assume you mean the connection between my engine and carb. The screws were loose on the connection, not the carb itself,but the metal from the engine into the carb. I tightened it.
You can take that thing (intake manifold) off, put some emery cloth or even sandpaper on a flat glass table, and sort of polish the mating surface of the flange down flat. The idea is to get an airtight seal at the flange where it bolts on to the engine. The engine surface is usually ok.
I put some gasket seal (a thin coat of permatex high heat copper stuff) on both sides of the gasket to make sure it doesn't leak any air. A little goes a long way, don't overdo it and have a gob of it in the air passageway.
The engine needs to suck its air through the air filter/carb throat, you don't want it to get in from any other place.
Another good thing to do is to make sure the carb is pressed onto the manifold as far as it will go until those notches in the end of the manifold are inside the carb. Some leak there, too.
Keep a little force on it as you tighten the clamp screw.