Hi Im new here and hoping I'm posting in the right spot. I'm also new to riding, and love it - should have done it earlier!!, I currently am on my P's and have a 2008 GS500. Great bike even though I haven't ridden anything else other than a scooter. My question is I have been ridding it since FEB 2010 and have been putting premium fuel, that is 95% octane, as the guy I brought it from said that is what you use. Lately the I have noticed when I downshift there is a type of pinging noise or more like gravel being shaken in a plastic jar kinda noise that occurs especially in the higher gears as I slow for a red light etc. I do use both brakes as I downshift so I am not just letting the engine do all the work. Does this occur because I am using the incorrect fuel???? Most service stations have changed their regular 91% to contain ethanol and since all the bad publicity about ethanol I am sceptical about using it. I get my bike serviced at the required/recommended service intervals at a Suzuki dealer and was only serviced a couple of thousand Km's ago that being the 10000km service. Am I doing/using something I shouldn't be as I want to look after the bike but having little or no knowledge of bikes I'm at a loss... Any info received would be greatly appreciated!! Thanks in advance!