235 johnson fuel trouble

[benrock]

i had some problems with the fuel bulb flatiing , i replaced the bulb and put in new fuel pumps , now its ok but i have a new problem , when i idle for a few min and then go it boggs down like its flooded and then when i get it up to 5500 rpm it backs down to 4500 but runs smooth from there ?<br /><br />please help

 

[angus63]

Re: 235 johnson fuel trouble

Sounds to me you may have a tank vent restriction or a fuel restriction between the tank and the bulb. Try with the tank cap loose to rule out the vent. Try a remote tank and different fuel line to rule out the restriction. If the bulb is remaining full, it is possible you may have an air leak btween the bulb and the fuel pump also. Checkem out good. Fuel filter replaced?<br />Good luck

 

[Silvertip]

Re: 235 johnson fuel trouble

Possible fuel restriction in the tank pickup, pickup tube, anti-siphon valve (if there is one), or in the line between the valve and primer bulb. The fuel pump may also have been weakened or damaged by the original fuel line restriction.