Mercury 2.2 stalls when throttle is opened.

[Bennyboat]

I have just bought a Mercury 2.2 1984 2 stroke. It has had little use and starts and runs fine but when i use it in the sea it starts to stall when i open up the throttle anything over about 25%.
The strange thing is that when it is at home and being run in the water bin full of tap water it opens up no problems at all.
Any ideas would be grateful thank you!

 

[gordmac]

When it isn't pushing a boat it isn't under load so doesn't need to produce much power. Just a guess but maybe there is a restriction causing it to run a bit weak? Maybe try cleaning the carburettor, in the old days we used to put the palm of the hand briefly over the carb intake to get the vacuum to suck stuff out the jets.

 

[Lakesailor]

Your main jet is blocked. Very common. Usually takes quite a bit of cleaning out as the 2 stroke fuel leaves a jelly-like residue which hides from view. Best to blow through with an air line when dismantled if available.
Loads of threads on the subject on here.

 

[davidbfox]

or the filter built into the petrol tap - it clogs easily.

 

[Lakesailor]

Worth checking, but the float chamber once full will give a fair few seconds of insulation from a blocked filter effect. The engine would rev when the throttle is opened, but die when the float chamber emptied.

 

[VicS]

Diagram of cab may help HERE

make sure parts #11 and 17 are completely clean

If you do not have an owners manual you should be able to down load one from
HERE

If a blocked jet is the problem you should find that partly closing the choke will help keep it going

 

[Sniper]

I've got one of these. Cleaning the carb is an absolute doddle - I've done it many times even while hanging on to a mooring after the thing has died on me mid way. The engineering is in the same tradition as the seagull - simple and accessible. I'm sure a quick clean of the jets will have it running properly again.