Small Engines (Lawn Mowers, etc.): B&S loses power/puts out black smoke when you accelerate?, engine model type, carburator

Question
It's a Murray 17.5hp Twin II I/C and all of a sudden it began to lose power when accelerating and black smoke started coming from the exhaust? It stalled, but I can restart and increase power. As soon as start to accelerate it loses power again, the engine surges, and black smoke comes from exhaust. I replaced the plugs and thought of changing the fuel filter? The air filter is fine, but I noticed a lot of fuel outside of the carburaetor when I removed the air filter. Please help- I need this one to last a few more years. A new mower is not in the budget now. Thanks

Answer
 Hello Garth:

 Send me the Engine Model, Type and Code Numbers and I can Better Assist you. However, It Sounds like the Carb Picked up Trash and Is Running Rich (the Black Smoke and Power Loss). The Float Needle is allowing too much Gas into the Carburator and Slightly Flooding it. I would Suggest Cleaning and Overhauling the Carburator. Hope this Helps. Let mwe know what Happens, Please.

 Good Luck

 Respectfully

 John