Nissan hp losing top end power

[DuaneJ]

Ok motor starts first pull idles great but loses top end power intermitently .Have noticed that the fuel filter has not been filling completly when this happens after pumping bulb the filter refills .have torn down and cleaned carb also have checked for air leaKs and restrictions in primer bulb and hose also tank vent is open .did pull apart fuel pump but dont see any tears in diaphram. at idle fuel filter stays full of full at higher range filter slowly empties and get bubbles in it till you pump primer bulb .could I need a new fuel pump or shold I replace tank and fuel lines including primer bulb

 

[DuaneJ]

Re: Nissan hp losing top end power

P>S what year is it NS8B 3B2-161110

 

[randrball]

Re: Nissan hp losing top end power

my 25 did the same thing. it turned out to be the male fitting on the engine. replaced both the hose female and engine male; problem solved. the fittings are equipped with check valves which open when connected, but the engine female fitting was not opening completely causing my engine to starve for fuel. pumping the buld always worked, but gets quite annoying.