1990 Johnson Evinrude "ES" 60 thru 70 Service Manual, P/N 507873, Page 62Get 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 system It is very important that all boat fuel system components are of the correct capacity and that they are properly installed ABYC's Standard H-24 and ICOMIA's Standard No17 are accepted as industry standards and should be referred to for additional information
INote permanently installed fuel system pumping capacity with excessive restrictions could exceed the VRO unit's
and cause poor engine performance or serious powerhead damageTo evaluate the restrictiveness of permanently installed fuel system, refer to Testing Fuel System, this SectionR ecorn mendations 1Fuel Tank Pickup Tubeminimum inside diameter of 3;'8 in(9,5 mm) is required for V6 and larger enginesA minimum of 016 in (7 ,9 mm) is required for V4 and smaller engines, but 3;'8 in(9,5 mm) inside diameter is preferredTwo separate pickup tubes are required for dual engine installation2Pickup Tube Filterto be constructed from stainless steel No304 wire cloth30 mesh, with wire diameter of .0100 .012 in (0,25-0,30 mm)A 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