I think the owners manual was calling for 10w 30 but I cant find that weight on motosport outlet. It looks like they are mostly selling 10w 40 for bikes. I usually ride in cooler climates at a little elevation. I dont believe in synthetic oils, just another gimmick.... I also like Belray lubricants because NASA uses them. I was looking at that Belray Mineral 4T 10w 40 EXL 4 stroke engine oil. Any other recommendations?