I had the same question and got several opinions. I decided to contact Precision Concepts and get true expert advice. I have an 06 450r. For the motor oil, they recommended Honda HP4M 10-40 at the high line of the oil sight glass with the engine warm. (Change the oil and filter. Fill with the recommended amount. Start the bike and let it run for a while. Re-check and fill to the high line mark). They also recommend HP4 in the tranny. (NON MOLY SYNTHETIC). The 06 calls for 670 ML. You can use up to 750 ML. Precision Concepts use the large Hinson clutch cover and use 900ML. Hope this helps.