Oil service CRF450,type of oil and quantity

when you go to the dealer to purchase the oil, just ask them. 4 stroke engine oil, is about 10W30. and the amount would be about just under 1 litre. sometimes it is stamped on the engine case, how much oil, in cc's.

Engine after draining: 660cc
Engine after draining and filter change:690cc
Honda HP4 Synthetic 10/40