2007-2009 Yamaha F15/F20 Outboard Service Manual, Page 57Get this manual
Periodic check and adjustment
Checking the fuel filter
1Check the fuel filter element 1Clean if there is dirt or residue and replace if damaged2Check the fuel filter cup 2Clean with straight gasoline if there are foreign substances and replace if cracked
3Remove the oil dipstick again to check the oil level and to check the oil for discoloration and its viscosity1
S6AG1050
S6AG3050
NOTE: Change the oil if it appears milky or dirty If the engine oil is below the minimum level mark a, add sufficient oil until the level is between and b
NOTE: Be sure not to spill any fuel when removing the fuel filter cup
Changing the engine oil