1998-2006 Yamaha F20/F25 Outboards Service Manual, Page 73Get this manual
_ 6Install: Engine oil filler cap Check: Engine oil level Refer to "Engine oil level"
Run the engine for several minutes, turn it off, and then check the engine oil level.If the engine oil is still not at the proper level, add or drain as needed
Valve clearance adjustment
Valve clearance adjustment should be made on cold engine, at room temperature1Measure: Intake valve clearance Exhaust valve clearance Use feeler gaugeOut of specification AdjustValve clearance: Intake: 0.2 0.05 mm (0.008 0.002 in) Exhaust: 0.3 0.05 mm (0.012 0.002 in) Measurement steps: Disconnect the fuel hoses CD, ignition coil leads and spark plug leads Remove the cylinder head cover Turn the flywheel magneto and align mark 1::::" on the driven sprocket with mark I::::) on the cylinder block Measure the valve clearance using the feeler gauge for cylinder #1 Align markon the driven sprocket with mark" 1::::"on the cyl inder block and then measure the valve clearance for cylinder #2