1990 Johnson Evinrude "ES" 40 thru 55, P/N 507872, Page 77Get this manual
3Anti-Siphon Valvesafety standards require permanently installed fuel systems to have anti-siphon protection This protection can be afforded in two ways All fuel distribution lines must be secured above the highest fuel level when the boat is in its normal, unloaded, static floating position Each fuel pickup tube must have an anti -siphon valve installedAnti-siphon valves used must have pressure drop of no more than 2.5 inof mercury (Hg) at flow rate of 20 gallons per hourThe following OMC valves meet this requirement: PIN 173273 for PIN 173274 for PIN 173275 for 516
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