As long as the non-return valve is working ok (it's on the inside of the r/h casing) then it shouldn't 'wetsump' but TJ is correct about the oil levels.....take the bike for a run, then let it stand for 10 mins, then, with the bike upright (not leaning on the sidestand) check the level...i always check the level after the dipstick has been screwed in (or at least make an allowance if you are dipping it without screwing it in/out)