I consider myself an above average mechanic so when I couldn't figure this one out it really bothered me to conceed to take it in to the dealer. Here goes. The 1999 Yamaha has an overspeed sensor,(rev limiter) that goes through the CDI unit(the brain box). My CDI unit decided to start telling the overspeed sensor that 3000 rpms was now redline and shutting the motor down after the buzzer went off. Anytime that something happens possibly damaging the motor the buzzer will go off and your motor will run rough causing you to back off the throttle. There are quite a few sensors in your motor that at some point or another run through this CDI unit. After purchasing a manual I did learn quite a bit about my motor. If anyone else out there has a yamaha 115 to 250 HP from 1998 to 2002 I have the manual. Feel free to drop me a line. My email is ccm883@aol.com . I want to get my moneys worth out of this book.
