Straight Up
Do what you like but this works every time........
Too Check oil level anytime ---First vertically balance the motorbike on its wheels with your hand or a partners hand---that position shows the most accurate level of oil in the window...and yes-- the sight view is sensitive to off balance positions.
I place a block of sorts under the kick stand to balance the bike close to vertical...just enough to keep the bike from falling toward the view window.
Do not work on the bike on the block--only on the side or race stand.
The oil/filter change----begins by removing the filler cap then I drop the old oil, then remove the filter, then clean the mating surface on the motor.
When emptied---replace the oil drain bolt, fill the new filter 1/2 full of oil and screw on correctly, then add 4 quarts of oil. Run motor and check for proper circulation. If all is well check view glass -- after motor has been off a few minutes. That procedure has worked for me and no adjustments have been needed.
Experienced people will do basically the same thing but may use different sighting positions for checks with the bike on the side stand.
