I've got a new Briggs & Stratton 7.5 that has a carburator problem. It tries to start but dies, checked the plug and its wet with fuel. I removed the carb and checked the float/needle and it's working correctly.
I finally got it started and it ran fine but I'm sure it will be a probelm the next time i try to use it. It runs great once you get it started.
If the engine is new, it should be under warranty. However, manufacturers will NOT warranty problems caused by fuel - it must be a manufacturer's defect to qualify for warranty. So, if your problem is caused by fuel then you need to investigate your fuel more closely. Is your fuel more than 30 days old? Do you use a fuel stabilizer? If so, which brand? Is your fuel container contaminated? Do you purchase your fuel from a "nationally recognized" supplier?
You mentioned that the plug is wet. Are you over-choking when cold starting the engine? Are you using the choke when the engine is hot? Is the air filter dirty - happens quickly on push lawnmowers when used in dusty conditions.
What did you find when you opened up the carburetor? What else have you tested?
There is an adjustment in the area where the plastic air vane and the metal thermostat arm are located. Before trying to adjust, check to see if the choke moves when you try to start it. It should open as soon as if starts, which in your case just before it dies.