If you’ve got a 3.5hp (4-stroke) Tohatsu/Mariner outboard that will not rev up after you’ve cleaned the carburettor there’s a good chance you’ve accidently lost a vital part and you probably didn’t even notice it fall out.
Don’t worry you’re not the first person to do this and you certainly wont be the last!
The little rubber plug (part number 8M0060417) sits inside the orifice right next to the main jet in the bottom of the carburettor and blocks fuel from being pulled up into the body – if its not present the carb will not fuel correctly and the engine will not run at open throttle.
If you cannot find it there is an alternative!
So you’ve looked everywhere and its genuinely vanished don’t panic, if you’ve got some chunky O-rings on hand that are the thickness of the hole just cut a small piece off about 4mm long (it needs to just touch the bottom of the float bowl to hold it in place) and poke it in the hole.