Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Welcome to JUST ANSWER small engines, let me try to help you !! I don't know it all, but maybe together we can get you a satisfactory answer!
Anytime the governor arm starts moving and engine dies, the engine is starving for fuel. Check the fuel supply from the tank, to the carburetor. You may have trash in tank, or the outlet line, or fuel filter may be plugged with water or debris from tank.
Accumulation of debris as it runs, and that makes me think there is debris in tank.
Does engine start smoking? Do you find plug fouled? How long after it quits will it restart?
If it will not restart, take a spare spark plug and when it quits, remove spark plug wire, attach it to the spare spark plug, and with the spark plug grounded, see if it has spark when cranking. If not spark, the ignition oil is failing. If it has spark, problem is the fuel supply.
No ,it is external, not an internal problem.