I stock Redline 20w50, MTL and Shockproof Heavy gear oil. I use these on my Harley , that is more 1/4 mile race bike then street bike. I called Redline and they thought I should use 10w40 oil in the Yamaha. I hate to stock two different oils. I feel the 20w50 Redline synthetic should work in my FJR. What is everyone's opinion on this idea? Also, when I changed gear oil at 600 miles, I put Redline Shockproof Heavy in shaft drive. This gear oil is synthetic and has a rating of 75/250. It works fine. The way this stuff clings to gearing is amazing.