the dealer put 10w-40 in my bike when i had it in for maintenance. when it was time to change, i put bel ray gearsaver in my bike(2003 kx 125), and it made a world of difference. the clutch hooked up so much better and the friction point was not frustratingly wide as it had been with the 10w-40. i would never go back to the 10w-40.