Wish it was a straight forward answer, but it depends on whether the Engine is Aluminium or Cast Iron and engine size (Model Number)!.
Surprisingly, it requires SAE 10w-30. 30w is accepted use in this Country as in the engine when used in average temps.
Oil Change periods differ also with Engine size/type :-
If your Aluminium Engine Model Number is 130000 or LESS, then it states- you only need to check 'n' top up the Red'c'n Gear level every 100 hours!.
Ali Models 140000 upwards, it states- change the Red'c'n Oil every 100 hours.
If the engine is Cast Iron, the Red'c'n Gear is lubricated using the Engine Crankcase Oil, so dealt with during Engine Oil checks 'n' change rate (25 hrs on all types).
Points to note is not to mix up the Fill/Drain Plugs The Fill Plug should have a breather vent hole.
Regards.