I checked today; the only difference between the 9.8 and the 8 hp has a smaller carburetor and smaller air induction. I purchased the 9.8. Bill Dunn ************** Get trade secrets for amazing burgers. Watch "Cooking with Tyler Florence" on AOL Food. (http://food.aol.com/tyler-florence?video=4& ?NCID=aolfod00030000000002)