Bogging out at full throttle

[Tommy Hughes]

I have a 1981 22" Nordic day cruiser with twin fuel tanks, on one tank I can get full throttle no problems. On the other tank I get just over half throttle and motor cuts in and out on me I can't get over 3/4 throttle tops. HELP ME OUT FELLAS. Thanks for your help

 

[guyjg]

Either the fuel tank switch is plugged, the tank hose is swollen inside or the antidrainback valve is plugged...also maybe the tank pickup is buggered. Tank vent may be plugged w/insect nest.