i bought a 2000 king quad and was told to use motorcycle oil (10w40) because of the clutch lubricants Is this accurate or use just regular 10-40?

 

You don't have to use motorcycle oil, but you do have to use an oil with no friction modifiers. 1 oil I highly recommend is Shell Rotella T6 5w40. It's a full synthetic diesel grade oil (has lots of anti wear additives) but no friction modifiers. If you use regular motor oil you will ruin your wet clutch. I've done a lot of testing with Blackstone Labs with my Suzuki Arctic Cats. 400 and 500. The T6 showed much lower wear even than Mobil 1 Euro Formula. I use T6 in my AC 700 gas and AC Diesel.