1998 Johnson Evinrude "EC" 90, 100C, 105C, 115, 150, 150C, 175 60 deg. LV Service Manual, P/N 520210, Page 71Get this manual
5If your reading is greater than inHg, you must test each boat fuel system component for excessive restriction before continu ingRefer to Boat Fuel System Recommendations, this section, for component descriptions 6If you suspect the anti-siphon valve, perform these tests Remove anti-siphon valve from fuel tank and install adapters and appropriate size clear hose as shown Fill clear hose with water until "X" dimension is 20 in(500 mm)Water must not run through valve Increase water level until "X" dimension is 25 in(630 mm)Water must begin to run through valve before reaching 25 in(630 mm) Replace the anti-siphon valve if your test results are different7If your reading is less than inHg and air bubbles are visible in the clear hose, check entire boat fuel system for air leaksRepair leaking connection
An air leak into fuel supply system may not create visible fuel leak until engine is turned off and fuel system is pressurized by the heat of the sun
Transparent Hose
Adapters Tank End Anti-Siphon Valve Engine End