mikey,
The manual does call for 89 octane but you have to remember this is just a suggestion, same as speed limit signs are.
One problem you will run into usimg higher octane than is really needed is carbon buildup. I use 89 all the time before the big bore and had minimal carbon buildup. Some others I saw ran high test exclusively and had massive carbon build up. I read somewhere, do a google search for carbob buildup, that using high octane gas will not burn completely due to the extra additives sinse the gas is not in the motor long enough in a bike and the motors are relatively low compression rates compared to race machines that require high octane.. Kind of made sence to me, maybe I oversimplified it though. I will now run just the Sunoco 91 octane and will switch to the 93 if I get any pinging. Pinging is the key. If it pings, go up in octane, no ping you can go down until you get pinging than back up. Also depsnds on the brand, I always used Sunoco with the dedicated hoses and als use mobil on ocassion.
