SURGING ENGINE: This is a dirty carb, not the governor.
99% of all snowblowers, tillers, generators, log splitters, pressure washers and other equipment are designed to run safely run @ 3600 rpm max.
Mowers engines are designed and can easily handle a max of 3600rpm...However lawnmower blade speeds are goverment regulated and since the blade is directly connected to the engine they are sometimes limited to speeds closer to 3200rpm. Check your mower mfg for specs. Some mower manufactures lower the rpm only to reduce noise from the engine.