by Mike
(CA)
i have a yamaha f200 2017, 550 hrs. no problem till recently, take it to service every 100 hours. Yesterday i was coming back from fishining and noticed the revs drop from 3800 to 3600, and a slight buzz/whining sound. i got up to 3800 again and the engine seemed to misfire--the sound of the engine fluctuated. Docked up. Today i went out on a test cruise , the problem and the whining sound is still there, ( not at neuteral). I started going on a plane and at 3600 the engine started whistling loudly with strange noises and the engine backfired/ misfired. i then turned around and docked up. iI checked the belt, looks brand new. Any help is greatly appreciated.