View Full Version : Yamaha 200HP V6 Shuddering and dropping in revs

Jesse Jenden
04-27-2006, 03:21 PM
I have a 200hp 2 stroke Yamaha. 1999 model and when cruising at 4000rpm the motor will just start to shudder badly and drop right off in revs. Seems to clear when i cut the throttle right back and then go again. Does it randomly. Have fuel/water separators so shouldnt be water in fuel ..Any help would be great

05-03-2006, 07:49 PM

When it does that try to pump the fuel ball...if the RPMs go back up it is probably one of your fuel diaphrams (usually the top one; used for higher RPMs) If you do not want to do that, then blow air into the fuel diaphrams thru the intake hose...if air comes out the back thru a little hole replace the diapharam. Cheaper to buy the whole diaphram from Yamaha dealer."