Gents,
What oil dya all run?
I see that 5wt-40 is the required stuff, but what brands are in / out of favour?
One shouldn’t go far wrong sticking with OEM oil of course, but there’s no guarantee that’s the best stuff.
Another ‘illness’ of mine is old British motorcycles, these are ‘flat tappet’ engines and recently a fantastic oil comparison test was done by a guy in the US. It was very interesting as many myths were bust, in particular that many high end, well known, branded oils broke down quickly in a flat tappet type scenario.
In the M159 the cam acts directly on the buckets, there are no rollers and the buckets do not rotate, so we essentially have the same action as a flat tappet engine.
Many modern oils are not designed with this action in mind.
In the aforementioned oil test, Royal Purple came out on top, closely followed by Bel Ray. I’m therefore thinking that 5wt-40 Royal Purple would be a good choice.
Are there any strongly held opinions regarding the best oil for the M159?