1990 Johnson Evinrude "ES" 9.9 thru 30 Service Manual, P/N 507871, Page 62Get this manual
Fuel Tank Servicing L!J Lll tune-up or major repairDrain tank at an outdoor location, away from all possible sources of ignitionA drain screw is provided in the fuel tank upper housingShake the tank before draining to mix sedimentsClean the tank by flushing with clear gasoline or solventPrimer pump, screens, etc may be inspected aild cleaned as described belowRefill the tank with the correct fuel mixtureCleaning and Inspection If the tank or hose appears to be leaki'ng fuel or fumes, pressure test tank and hose assembly before doing any disassemblyClean the fuel tank and inspect for rust or leakageReplace tank if badly rusted or if it has developed leaks in the metal body