[Harold_89_911]

Same problem with my Poulain about 2 years ago. Checked spark plug and governor and both were fine. Did a "rebuilt" of the carburetor and that solved the problem completely. The kits are available from the local hardware store (Lowe's for me). In my case it was just a rubber membrane with some holes cut out of it. Removed 4 screws to split the carburetor horizontally and replaced the rubber piece, while keeping track of which loose pieces were above and which ones were supposed to be below the membrane. Hopes this works for you too.

While reading up on this on the internet before my fix, I read a warning not to run it while it is surging. The surging is caused by the mixture being way too rich and that can wash the oil from the cylinder and do permanent damage to the engine.