I'm currently using a Sierra 90 GPH/10 micron filter at over 90% efficency water/fuel separator. I'm thinking about switching out to a Racor, water/fuel separator with the clear bowl. I've read here and there that Engine HP divided by 10 will give you an approx. flow rate of fuel required by the engine. (Or is this an approx. consumption per hour calculation?) In my case, (2000 Model Johnson 200) this will equal approx. 20 Gallons/Hour. I'd like to drop down to the Racor 60 GPH instead of using a 90 GPH given the space required for the 90 GPH Racor assembly, and in my case it seems to be overkill. I've tried to find an accurate calculator, or some decent literature on the subject, but I'm coming up empty handed.
