mercury 402 that misses

[robc1963]

hi guys,
I have a Mercury 402 1979 idles well but when i give it 3/4 to full throttle seems to miss and lack power . was running ok on the river for a few hours then all of a sudden started playing up.cleaned the plugs but that didnt work , have you any suggestions please,
rob

 

[Windykid]

Re: mercury 402 that misses

carb rebuild, or some seafoam?

 

[Windykid]

Re: mercury 402 that misses

Bad fuel, vent closed?

 

[crem1]

Re: mercury 402 that misses

Could be fuel pump problems but I would say that it needs idle screw adjustment or thorough cleaning in a solvent and rebuild it with a new carb kit

 

[robc1963]

Re: mercury 402 that misses

thanks ,
found a lot of crap in the fuel pump, cleaned the carb but still seems to miss at hi speeds also i get a big electric boot though the control box and the plugs foul up eazy could this be the rectifier coil or switch box?
robc1963