in my ex500 I run castrol semi-synthetic 20W-50. I know triplesec man runs mobile 1 full synthetic 15W-50.
pretty much any oil will work good as long as it doesn't say 'energy conserving' on the seal. and it needs to meet all the requirements in the manual. which is nearly every oil out there. you just have to try different oils and see which one your bike runs best off of.
