by Mel
(Columbia, SC)
I have a 2004 4 Stroke Yamaha 115 on a Key West 186DC. The boat was running approx 35 mph initially after launching it with 5 adults. I went to idle speed to go through a no wake zone and when I throttled the engine back up it would not run over 15mph and 4000 rpm’s. After putting along, throttling up and down with no change, I started weaving the boat back and forth and it gradually increased speed and rpm’s until it was running 35 mph again. Anytime I went to idle speed or stopped I would have to go through the same steps to get it back up to speed. Seems like a fuel problem to me. It has a relatively new water separator filter on it, was changed a couple of months ago and a new fuel filter. Any suggestions on what to check next?