20 hp mercury

[red]

I have a 1980/81 20 hp mercury that idles fine, but bogs down and or surges while in gear and under acceleration. It runs a little better sometimes with the choke out a little. Carb, fuel pump have been rebuilt, along with new water pump and new fuel tank. Running out of money and patience. Any help would be greatly appreciated.

 

[MERCMAN]

Re: 20 hp mercury

Sounds like your air fuel mixture adjustment is to lean intial setting is i beleive is one turn from lightly seated. or possiblely still have a blockage in carb you say it is better with choke out this tells me your on the lean side check idle tube.