I recently bought some yamalube 2r for my 03 yz125 and ran it for 20 hours or less at 40:1. It immediately started spewing a thick black sludge from my power valve vent. I thought it was just the switch from bel ray. Fast forward to 20 hours later where my bike stops running due to yamalube fouling my plug and gumming my engine up. It is costing me a new plug and tearing my top end down to clean the gunk out of everything. Just so no other unlucky souls have this happen to them, don't go cheap, stay as far away from yamalube as possible.