I've been having issues with my Zeal lately, and I took it in for a tune after doing other work to it to save a bit of money. (Checked/replaced fuel lines, fuel filter, oil, oil filter, spark plugs, put on a new undamaged exhaust) Anyway when I took it to be tuned the guy asked what fuel I used to which I replied I generally use the shell premium. I was told to totally avoid shell for the bike, which I can understand since the fuel I have been getting lately has been terrible, and I've been avoiding it anyway. However I was also told that the zeal can't handle premium fuel? I've pretty much always used it, just because of the extra kick and just thought this seems a bit strange, can anyone with experience or knowledge of zeal's shed some light on this issue.