Go to a second-hand book store.
Pick up a used owners-manual on any basic m/c or a Clyners manual on any basic m/c.
THEN you can go through the general maintence & even deeper into what makes a m/c tick.
That will save anyone on this board from trying to ask such questions.
How do you think, we as new m/c dealers after WWII picked up on all the British irons we were bring over --- we bought NEW WorkShop Manuals directly from the manufacturers.