This sounds like a perfect opportunity to flog my favorite..Redline!
"As part of Red Line's all-new Powersports line, these High Performance Motorcycle Oils are fully-synthetic formulas specifically created for the high demands of the latest high-revving four-strokes motocross bikes and ATVs, Sportbikes, and V-Twins. Available in popular viscosities of 10W40, 20W50, and 20W60, these ester-based products contain the anti-wear chemistry demanded by mechanics and enthusiasts. The levels of zinc and phosphorus blended into these lubricants are among the highest in the industry and combine well with Red Line's chemistry, designed to seal piston rings for more power, fight fuel dilution, extend drain interval and provide stronger film strength over a range of temperature. This oil also features lower levels of friction modifiers for superior wet clutch operation. Excellent thermal stability, oxidation resistance, cleanliness, and ability to lubricate hot metal make Red Line High Performance Motor Oil a superior lubricant. Recommended for JASO MB, API SJ, SG, & SH."