I'm on my second build and this one will be with the grubee stage II 4-stroke motor. My first build was with a china girl. I live near Minneapolis, MN thus there aren't many hills around here. I weigh a whopping 155 and will be mounting the engine on a Shwinn Jaguar from target. The sprockets I've been considering are the 41 tooth and the 36 tooth "racing sprocket." I don't care a whole lot about going fast, however it seems logical to me that running my engine consistently at lower RPMs should equal longer engine life. My biggest concern with the 36 tooth is getting up the few hills we have here in MN. Any suggestions?