You’ve gone through the tedious trouble of disassembling your carburetor, properly cleaning it, and reassembling and setting everything to spec. Now it’s time to install it and get the engine started.
Before installing the carburetor you need to make sure all the old gasket has been removed from the manifold. You may need to take a razor blade to clean up small bits still left bonded to the metal. If the gasket is really stuck, this may be a bit time consuming. Do a good job because old material could possibly shim one end the the carburetor up, causing a vacuum leak.
If the surface is perfectly smooth and flat, you can use the gasket without any sealant. If the surface has a few nicks and cuts from removing the gasket with a razor blade, you can use a light coating of a product like Gaskacinch. It is a rubberized contact adhesive which gets into the small crevices of an imperfect gasketed surface.
When tightening down the carb to the manifold, progressively tighten the nuts and don’t think you need to be he-man putting them on. Good and snug is good enough. Over-tightening can break the ears off or cause distortion of the throttle body.
Hook up the linkage. Do not spray it with lubricant. Most carburetor linkage is designed to be sloppy so that it will continue to operate once it gets dirty. Spraying it down with grease will attract dirt to the linkage and will cause issues.
Leave off the air cleaner while you are initially getting it fired off. You need it off to check for leaks and check the function of the carb.
Hook the battery back up (you did disconnect it didn’t you?). Before cranking the engine, spray a few bursts of carburetor cleaner down the intake. Crank the engine. It should fire off and then die. You may need to do this several times before the engine will run on its own.
If you have an electric fuel pump, the float bowl will be filled up when you turn on the key. If you have a mechanical pump, you will need to run the engine on carb clean until enough fuel has been pumped into the float bowl to run the engine.
If everything goes right, the engine will settle out into a nice idle. When it doesn’t (and this is likely) you will need to do some troubleshooting and tuning. That is the subject of my next post.