Exhaust emissions from five gasoline-fueled, air-cooled utility engines were measured using two types of steady-state procedures, and some measurements were taken during transient operation. The engines included one and two cylinder, two and four stroke models with 2 to 18 hp. The two procedures used for small engine tests were a 9-mode procedure which was being recommended by SAE at the time the tests were run (early 1971), and a modified version of the 'EMA-California' 13-mode procedure. The exhaust products measured included hydrocarbons, CO, CO2, O2, light hydrocarbons, total aliphatic aldehydes, formaldehyde, particulate, exhaust smoke. The engines were operated on small electric dynamometers, and the emissions results are used in conjunction with statistics on utility engine population and usage to estimate national emissions impact. (Modified author abstract)