Yamaha 20 fourstroke no power

[Hoppi84]

So I took the boat out yesterday and it fired right up and seemed to idle good so I pulled it off the trailer and docked it... Pull the trailer and hop in boat and everything seems good til I get out of the no wake and try accelerating... It rev up and started taking off but never wanted to get past 3500rpm.. I fished for a bit and was able to get to about 4900 but was a struggle with lots of hesitation and surging.. the motor never died just lacked mid and full range.. I did order a new fuel hose and pulled the carb to be cleaned and will change plugs... Any thoughts??

 

[Hoppi84]

So this is the second time I've had the carb off and forget to remove the fuel line from motor so the cowl pretty much filled with gas... Should the fuel pump be allowing fuel to pass?? There was a bit of varnish in the main jet....

 

[99yam40]

there are check valves in the fuel pump, but they just keep gas from flowing back out of the motor not to the motor.
so yes fuel will flow out of the tank thru the pump if pressure builds up in the tank