1995 Johnson/Evinrude Outboards 25, 35 3-Cylinder Service Manual, Page 63Get this manual
Boat Fuel System Recommendations Purpose This information is provided to assist you in evaluating boat's permanently installed fuel systemLarge outboards require boat fuel system that has high fuel flow rate and low pressure drop across the entire systemIt is very important that all boat fuel system components are of the correct capacity and that they are properly installedABYC's Standard H-24 and ICOMIA's Standard No17 are accepted as industry standards and should be referred to for additional informationINotel permanently installed fuel system with excessive restrictions could exceed the fuel pump's pumping capacity and cause poor engine performance or serious powerhead damageTo evaluate the restrictiveness of permanently installed fuel system, refer to Fuel Pump Servicing, this sectionRecommendations 1Fuel Tank Pickup Tubeminimum inside diameter of 3S in(9,5 mm) is required for V6 and larger engines3S in(9,5 mm) is preferred for V4 and smaller engines, while minimum of 516 in(7,9 mm) is requiredOne pickup tube per engine is required in mUlti-engine installationsNo304 wire cloth, 100 mesh, with wire diameter of 0.0045 inA cylindrical screen equal to pickup tube outside diameter and in(25,4 mm) long will provide adequate surface areaThe screen should be horizontal and slightly above the tank bottom