My '99 800 suddenly began starting very hard and having no midrange or top end power. I am not getting an FI fault light ( yes, the FI light works when you first turn the key on). I have had the tank and airbox off and can find no loose vacuum lines or wires anywhere. It has a PC 4usb which I disconnected to elminate it from being defective, it runs worse with PC disconnected. PC is now re-connected. The bike wont take throttle unless you give it gently, then it will rev. A good friend of mine (Master Toyota mechanic) helped troubleshoot it. After much discussion and trying different things, he tried clamping the vacuum line going into the MAP sensor and the bike revs like it should, on the stand. I replaced the MAP sensor with no change. The bike is very clean and has been well taken care of. Upgraded R&R, brand new battery 14,500 miles, K&N filter, PC4usb and TBR slipon exhaust. Any help on this issue will be greatly appreciated.
