40 hp plug fowling

[Fish Regulator]

I have a 1982 40 hp mercury 2 stroke I have been 50:1 mixture as stated in the repair manual I have. The problem is when I put new plugs in it it runs fine for five minutes then it begins to sputter and bog down so I remove the plugs and they are covered with oil if I clean the oil off I can get another five minutes out of it. I thought that maybe I mixed the fuel to rich so I disposed of the fuel and remixed only to have the same problems again. Any help would be apreciated.

 

[Fish Regulator]

Re: 40 hp plug fowling

Should I rebuid the carb.

 

[rverano]

Re: 40 hp plug fowling

I always mix into an empty 6 gallon tank with the bottle of oil to make sure it's correct. Have you tried adjusting the mixture while in the water. The manual should tell how to do this. If the carbs have not been rebuilt they problably should. A clean carb will help when setting the mixture.