Originally Posted by Sandman

Operators manual and Haynes both say the same thing:

1.Start the engine and let it warm up for 10 to 15 minutes then turn it off.
2. Support the bike upright on level ground. Allow it to stand for a few minutes for the oil level to stabilise.
3. Unscrew the cap and wipe the dipstick clean.
4. Insert the dipstick so that the cap contacts the threads but do not screw it in.
5. Remove the dipstick and the oil should be between the upper and lower level marks.
6. If the oil is on or below the lower line, top up the engine with recommended oil.