The paper presents emissions data obtained from seven lawn mower engines that were tested using three duty cycles: a six mode steady-state test, a quasi-steady-state test, and a transient test. A comparison of emissions from the three duty cycles is made for non-methane organic gases, carbon monoxide, nitrogen oxides, detailed hydrocarbons (percent of total organic emissions that are paraffin, olefin, aromatic, or acetylene), and toxic compounds (benzene, 1,3-butadiene, formaldehyde, and acetaldehyde). Dufferences in ozone potential are also determined and reported for each duty cycle. The study includes both regulated and unregulated (not certified to any emission standard) test engines that have a wide range of emission rates. Results indicate that regulated emission rate differences due to duty cycle are fairly small (less than ten percent on the average). For over half of the regulated emission data, there is no significant difference in emission rates between data obtained using the steady-state and transient duty cycle. Emission comparisons are even better between the quasi-steady-state and steady-state data.