The oil in my bike gets darker within 200 miles, even when the bike was new,
I was told it might be blow by but I have no oil consumption at all x 4000 mile
I know at least 1/2 a quart of old oil remains in the engine after draining and mixes with the fresh oil and instantly darkens it.
The oil after 3k looks very dark but not opaque, bike never smokes & spark plugs in perfect color.
I use amsoil and change the filter every other oil change.
Is this something to be concerned about ?