Did a good chain cleaning and put on my spare rear tire on the busa Wed and went out for a ride. Rode about 100 miles and made a stop for gas. The premium gas had a sticker on the pump that said 10% ethanol, but no such sticker on the regular 87 octane that I use, so I filled up. $16 later my tank is full and off I go. About 10 miles down the road my bike feels like it is running flat at low RPM. I get to a stop light and the idle is moving from 1150 up to 1600 and back down again. It feels like a vacuum leak, but although I had the fairings off and the tank was lifted so I could check the air filter, I didn't mess with anything else by the engine. The busa has 29K miles on it, and I have not sync'd the throttle bodies as the bike has ALWAYS ran great and smooth. The only thing I can think of is I got ethanol or some bad gas. No FI codes have shown up on the dash. I ran as much gas as I could short of running out of gas, and filled it up to the top with good quality gas from the same station I get it from all the time. It doesn't seem quite as flat, but the idle is still jumping from 1150 to 1600 RPM's. I will look at all the vacuum lines and such tonight, and will probably get the throttle bodies sync'd althought I fail to believe they would get out of wack all at once. Any thoughts from you guys on what else I need to check? I would appreciate your feedback.
