Regular changes are important. Two chains (primary and cam) and a gearbox, quickly reduce oil viscosity by shearing the oil's polymer chains. The viscosity you start with isn't what you drain out.
Aye,
that's good advice, I change the oil and filter every 1,500 miles and chuck in 10w/40 semi syn from where ever.
But my CB750F1 has three chains (2 primary and a cam chain).
