Re: 3hp OMC crankcase question Home › Forum › Ask A Member › 3hp OMC crankcase question › Re: 3hp OMC crankcase question fleetwinUS Member - 2 YearsReplies: 4737Topics: 46 June 29, 2018 at 10:27 pm #78694 Yeah, a leaky crankcase will most likely create a lean condition…Tell us more about the rich running condition…