well, I'm changing the oil in my 07 bandit 1250s, it has 10,000kms, it has normal mineral oil in it now, want to switch to synthetic. I bought some CASTROL SYNTEC 10W30 API SM,SL,SJ,CF (it was on sale), I know that it recommends 10W40 with SF/SG or SH/SJ in API with MA in JASO, but is there any harm or problem with using this 10W30 product? They did not have 10W40. I'm new to this, just looking for a honest answer!! thanks