A 4-cycle engine turns a rotary blade at 3,600 rpm; $130–$900. Shown: Craftsman 38814, $180; craftsman.com Pros:
Has the most power, features, and options; no limit on running time as long as the tank has fuel. Cons:
Noisier than other types; heavy; needs the most upkeep; difficult to start if not maintained; storage-space hog.