I recently got a 05 Z1000, have been riding it for few weeks now. The 3rd week the bike stalled as if it was running out of gas after maybe around 40-45 mins of riding, it was rush hour and I was stuck in traffic. It took a few tries and the it started up again, would run fine then again stutter and stall. I have to keep the rev really up to keep it going..I was close to home when this kept happening. The next day morning it ran all perfect with no problems .. perfect response when you gave it gas was running smooth. I got to the mechanic ..he did a check with battery, coolant, checked if all the cylinders were firing .. all seemed OK. He asked what gas I am using and I was using 89 which I did to all my previous bikes..and he said I should be using 91. I was like OK... and gave it a try ..bike ran well for 3-4 weeks and hope this was the problem. But no, happened again yesterday..stutter..stall..I was on the highway in traffic and an extremely Hot and Humid day...exactly the same scenario like before. Really don't know what would be causing this, I don't think its overheating.. I hear the Fan come on ...and I see the temp drop..never goes over 103-4 celsius. I have seen few guys on other sites describing the exact same problem as mine but there are no answers/replies with a fix. Has anyone here experienced this? know what could be the problem?