Well what is going on is the level of fuel being to high makes it easer for the engine to suck it in. In the manual section first gen factory manual there is a good picture of a carb and how it works. The higher the float and fuel level the less speed is needed over the venturi to suck fuel in Lower it about 1/16 to 1/8 of an inch. Re-adjust the carb so it runs good again and recheck MPG and the power, along with the smell. Every time you make a float adjustment you may need to adjust the carb. Also in the UTI training manuals there is more info on adjusting the carb and preforming a "lean drop" if it's necessary. That is if you have engine run on AKA dieseling. If after you adjust the carb float 1/16" and she is not up to the 16-18 MPG you can lower it again. It's just a process you will repeat until you have it the way you like it. Just keep in mind what ever you do, can be undone and we are all here to help. If you take pictures of what you do and post them using the built in photo attachment system you can help the next guy that comes along asking the same questions. Then it's in your attachment manager on the board.
Let us know how it goes.

OH and don't over torque the screws. It's eays to do.