jwilson
Well-Known Member
On Mercury top cover off two clips, then undo very tiny screws that attach plastic tips to the throttle and choke levers. Find dropped screws.
Then undo two long screws that hold control panel plate on. Pull off plate, having to slightly bend starter cord holder to do so. Leave connected by stop button wire and dangle down side of engine.
Now undo clip that holds on fuel pipe to carb and pull off fuel pipe. Don't lose little wire clip. Test fuel flow is good by opening fuel tap with jamjar under pipe. If dubious look at the filter mounted in the top of the tap inside the fuel tank.
Carb removes after undoing one clamp bolt. Pull and twist backwards till whole carb comes off. There is a small rubber O-ring that may drop out - pick it up from the floor.
Carb dissasembly now fairly obvious. Undo knurled top of slider and remove slide cylinder and main needle. No need to remove needle itself, just clean very thoroughly. Then clean again even more thoroughly. Undo two screws and remove float bowl. Clean bowl and plastic float. Usually some corrosion and fine grit in there - the nasty ethanol in modern fuel rots the alloy.
Last two jobs: clean the jet hole - some people poke a thin wire through but I prefer just to spray carb cleaner through and blow. Then carefully remove the pin that holds in the brass float valve spring and remove the spring and the little nail-shaped valve. Clean valve pointy end very thoroughly and spray carb cleaner down hole it came out of, blow clean.
Reassemble float valve and the rest of the carb. Put carb back onto inlet tube, not forgetting rubber O-ring.
Test engine before further reassembling. If not running properly repeat carb cleaning.
Problems with these engines are almost always carb or fuel, rarely plugs. I think my 14 year old much used Mercury is on it's fourth plug, probably its 20th plus carb cleaning. You problem COULD be ignition-related, but far less likely. I bought the Tohatsu version as a spare just before they switched to only selling four-strokes.
Then undo two long screws that hold control panel plate on. Pull off plate, having to slightly bend starter cord holder to do so. Leave connected by stop button wire and dangle down side of engine.
Now undo clip that holds on fuel pipe to carb and pull off fuel pipe. Don't lose little wire clip. Test fuel flow is good by opening fuel tap with jamjar under pipe. If dubious look at the filter mounted in the top of the tap inside the fuel tank.
Carb removes after undoing one clamp bolt. Pull and twist backwards till whole carb comes off. There is a small rubber O-ring that may drop out - pick it up from the floor.
Carb dissasembly now fairly obvious. Undo knurled top of slider and remove slide cylinder and main needle. No need to remove needle itself, just clean very thoroughly. Then clean again even more thoroughly. Undo two screws and remove float bowl. Clean bowl and plastic float. Usually some corrosion and fine grit in there - the nasty ethanol in modern fuel rots the alloy.
Last two jobs: clean the jet hole - some people poke a thin wire through but I prefer just to spray carb cleaner through and blow. Then carefully remove the pin that holds in the brass float valve spring and remove the spring and the little nail-shaped valve. Clean valve pointy end very thoroughly and spray carb cleaner down hole it came out of, blow clean.
Reassemble float valve and the rest of the carb. Put carb back onto inlet tube, not forgetting rubber O-ring.
Test engine before further reassembling. If not running properly repeat carb cleaning.
Problems with these engines are almost always carb or fuel, rarely plugs. I think my 14 year old much used Mercury is on it's fourth plug, probably its 20th plus carb cleaning. You problem COULD be ignition-related, but far less likely. I bought the Tohatsu version as a spare just before they switched to only selling four-strokes.
