[RCW]

Check the pulse line from the engine to the fuel pump, make sure it is attached and has not shaken loose in shipment. You will see the line running out of the crankcase through a breather water trap, and into the fuel pump to drive the diaphragm. If it gets loose the fuel pump will not work as it should. If the breather water trap fills with water and freezes, it can crack and leak the air pulses needed to run the fuel pump.

It could be a faulty spark plug, or a bad coil. If it starts right up after it quits, and will only run at an idle, then look to the fuel system. If it will not start right up after it quits, and you are sure it has fuel in the carburetor, then check to be sure you have spark at the plug wire. If not, it is the coil. A defective coil will quit when they are warm or start cutting out at higher engine speeds.

The problem sounds fuel related, and could either be the fuel pump, the filter, or the carburetor.

If it starts right up after it dies, and will idle with no trouble, but then dies when you give it the gas, I would check the fuel filter first. If that is not the problem, then you will need to disassemble the carburetor and pay particular attention to making sure the jets and passages are all open.

If it will not start right up after it dies, then pull the bold at the bottom of the carburetor bowl and see if gas runs out. If it does not, then it is either the fuel pump, the fuel filter, or the float needle has a blockage.

There is another thing you can try, and I would probably would before I did anything else once I knew the pulse line to the fuel pump was attached. Drain the gas and the carburetor, then put a gallon of aviation gasoline in the tank. If it starts right up and runs fine, then it is your gasoline. The automotive gasoline we have now days goes bad in just a few weeks, it has way too much alcohol in the blend and starts breaking down as soon as it is exposed to air.