repair mercury 15hp

[crossroofing]

I have a mercury 15hp, 2 stroke, when the motor is running and you accelerate it cuts out, it is like the choke is on.
When I remove the cover it seems to run perfectly, as if it needs air to operate.
I have cleaned fuel filter, i have check the air filter.
Has anyone got any ideas please.

[PeterM]

Had this on a 25..I think it was the carb adjustment ....and a rubbish in there which didn't help either.

[uncle al]

1/ old stale fuel
2/ carb setting about one and a half turns out from lightly seated
3/dirty,wrong or knackered spark plug
does it kick back when pulling to start If so it is a timming isue,with a strobe light re-set the timming as per service manual.
have you looked at the spark plug? If so what colour, black, white grey?
It reads as it is running to weak (lean) screw out the idle mixture screw a quarter of a turn
crap inside the carburetter, clean the carb

[m chappelow]

I would also have a look at the point end of the needle valve adjusting screw quite often the screw gets tightened down too tight ( as Uncle al said only tighten lightly seated )if its been nipped down too much in the past it can put a ridge or ring around on the taper point of the needle which will then make it hard to get any proper adjustment its either all or nothing .

[bmb779]

Originally Posted by uncle al

1/ old stale fuel
2/ carb setting about one and a half turns out from lightly seated
3/dirty,wrong or knackered spark plug
does it kick back when pulling to start If so it is a timming isue,with a strobe light re-set the timming as per service manual.
have you looked at the spark plug? If so what colour, black, white grey?
It reads as it is running to weak (lean) screw out the idle mixture screw a quarter of a turn
crap inside the carburetter, clean the carb

How often do you need to crap in the carburetter?

[uncle al]

bmb779,where do all these cheeky kids come from. Cant stand cheeky kids.but have a good day, my own fault I should have known better or worded it better.

[bmb779]

Originally Posted by uncle al

bmb779,where do all these cheeky kids come from. Cant stand cheeky kids.but have a good day, my own fault I should have known better or worded it better.

long timesince ive been a kid uncle al

[uncle al]

bmb779, you and me both ,but hell lets have a good laugh!

[bmb779]

Better laughing than crying uncle al,can't wait on weather improving to get back out in the boat again.