Hello everybody!
I'm new here and new to outboards but I'm going to try and keep it simple and hopefully can get some help. I bought a 2002 mercury 9.9 2 stroke outboard from a friend and was told it was put intro storage but ran fine before it was in storage. When I tried to start the motor it was locked up but I was able to get it freed by spraying penetrating fluid in the cylinders and letting it sit. I put new spark plugs in and after a couple pulls the engine started right up and seemed to run fine. It would smoke a lot on startup (mostly blue which I think is normal) but eventually would calm back down once heated up. The problem I ran into was when I revved the engine up it would almost misfire like a lean sneeze and then puff out a lot of white smoke it would then idle back down quickly and misfire again and puff out white smoke almost to the point of stalling and sometimes did stall. I didn't know what was happening so I pulled the spark plugs, the top cylinder spark plug looked basically brand new it was a wet but brand new, the bottom cylinder spark plug was the normal black but not fouled or anything and a little wet. I did check both cylinders for spark and they had spark. I thought it was weird that the top one was clean so I switched where they went so the clean one would be on the bottom cylinder and the black spark plug was on the top cylinder. I ran the engine for around 15 minutes and gave it some revs but still had the same misfire problem. I pulled the plugs again and discovered the black spark plug was cleaned off in the top cylinder and the clean spark plug turned black in the bottom cylinder. I did some research and was thinking it could be possible water intrusion because of a faulty exhaust plate gasket so I pulled the exhaust plate off and the gasket looked okay but did have some carbon buildup that could have caused a leak. I ordered some new exhaust plate gaskets and will see if it fixes the problem or not. I do probably need to take the carburetor apart and clean it too. Does anybody know what might be wrong or if I'm in the wrong direction?
I'm new here and new to outboards but I'm going to try and keep it simple and hopefully can get some help. I bought a 2002 mercury 9.9 2 stroke outboard from a friend and was told it was put intro storage but ran fine before it was in storage. When I tried to start the motor it was locked up but I was able to get it freed by spraying penetrating fluid in the cylinders and letting it sit. I put new spark plugs in and after a couple pulls the engine started right up and seemed to run fine. It would smoke a lot on startup (mostly blue which I think is normal) but eventually would calm back down once heated up. The problem I ran into was when I revved the engine up it would almost misfire like a lean sneeze and then puff out a lot of white smoke it would then idle back down quickly and misfire again and puff out white smoke almost to the point of stalling and sometimes did stall. I didn't know what was happening so I pulled the spark plugs, the top cylinder spark plug looked basically brand new it was a wet but brand new, the bottom cylinder spark plug was the normal black but not fouled or anything and a little wet. I did check both cylinders for spark and they had spark. I thought it was weird that the top one was clean so I switched where they went so the clean one would be on the bottom cylinder and the black spark plug was on the top cylinder. I ran the engine for around 15 minutes and gave it some revs but still had the same misfire problem. I pulled the plugs again and discovered the black spark plug was cleaned off in the top cylinder and the clean spark plug turned black in the bottom cylinder. I did some research and was thinking it could be possible water intrusion because of a faulty exhaust plate gasket so I pulled the exhaust plate off and the gasket looked okay but did have some carbon buildup that could have caused a leak. I ordered some new exhaust plate gaskets and will see if it fixes the problem or not. I do probably need to take the carburetor apart and clean it too. Does anybody know what might be wrong or if I'm in the wrong direction?
