05-10-25, 03:23 PM
Up to last June I had the very same problem on my 2005 model FZS1000 and it drove me nuts trying to diagnose it. It would stay reving up to 2500 revs when changing gear and when I would stop and eventually drop back to a slightly unstable tickover. I replaced the vacuum take off caps as one had a crack, checked the O-ring under the diaphragm cover, the diaphragms and the vacuum vents for the the diaphragms and they were chear. No cracks anywhere on the Intake manifolds. Eventually took the carbs off and opened the float bowls and everything in there was spotless. Took out the main jets and the O-Rings fell apart, removed the float valves and they look ok. Changed both of O ringson all the carbs and the float bowl seals as I had them off. Put the carbs back on and took it for a spin, running perfectly. Came home and checked the carb balanced which was fine. The O-rings in the Main Jets were only issue I found and was most likely bleeding excess fuel into the system. 2 months later I had a lot of surging when riging in traffic or touring around the back roads. Thankfully this turned out to be a dodgy TPS. Replaced that and had no issues since.