jimi
Well-Known Member
suspeect fuel problem, is there afuel filter I can check on it?
mariner 3.3 running rough and cutting out
- Thread starter jimi
- Start date
oldharry
Well-Known Member
More likely a few drops of water in the carb - and maybe in the fuel tank as well. Easy enough to get the carb bowl off, clean it, and get the jets out to blow them through. All should then be well.
If not, suspect the ignition pack, which is a workshop job.
If not, suspect the ignition pack, which is a workshop job.
MASH
N/A
Stale petrol is often overlooked - especially in items that lie unused for extended periods. If the fuel has been in the tank since the summer chuck it and fill with fresh.
VicS
Well-Known Member
You don't give year and model/serial numbers so it is going to be difficult for anyone to give specific advice.
First and easiest thing to check is always the spark plug(s). If it is old enough to have a points ignition system them the points are the next thing to check. Assuming it is an electronic ignition system then as said above its a workshop job to check really, but one would expect it to either work or not or to have an intermittent fault rather than to run badly.
Fuel problem then.
Fuel can go stale although if stored properly it will keep OK as well. Any doubts about it then flush out the fuel tank and use fresh fuel made using oil that is not ridiculously old. I've had the oil "go off". Always a good plan to filter the fuel mix as it goes into the tank if possible.
If you have an integral tank then there is probably a fuel filter in the tank outlet but if you have a remote tank then there is most likely to be a filter combined with the fuel pump (that's the pump not the priming bulb) and your owners manual will tell you how to clean it. With a remote tank check the fuel line and connection at the engine for air leaks. Pumping the priming bulb will help check. In either case check the tank vent.
Most likely, as already suggested, is that the carburetter needs cleaning. That means stripping down and removing the jet(s). Blowing through them is not always effective so you may have to clean them with a soft copper wire (nothing that will scratch them) after soaking in some cleaner. Take care when dismantling not to damage any gaskets or seals, or be prepared to buy new ones, and not to loose any small bits. Also carefully note how it all goes together, especially if you do not have a manual or a diagram. Check carefully for O rings or small washers as you take things apart!
If you cannot sort it out with advice from here then go to the Mercury/ Mariner board on the iBoats forums However if you do go there give the FULL model details.
First and easiest thing to check is always the spark plug(s). If it is old enough to have a points ignition system them the points are the next thing to check. Assuming it is an electronic ignition system then as said above its a workshop job to check really, but one would expect it to either work or not or to have an intermittent fault rather than to run badly.
Fuel problem then.
Fuel can go stale although if stored properly it will keep OK as well. Any doubts about it then flush out the fuel tank and use fresh fuel made using oil that is not ridiculously old. I've had the oil "go off". Always a good plan to filter the fuel mix as it goes into the tank if possible.
If you have an integral tank then there is probably a fuel filter in the tank outlet but if you have a remote tank then there is most likely to be a filter combined with the fuel pump (that's the pump not the priming bulb) and your owners manual will tell you how to clean it. With a remote tank check the fuel line and connection at the engine for air leaks. Pumping the priming bulb will help check. In either case check the tank vent.
Most likely, as already suggested, is that the carburetter needs cleaning. That means stripping down and removing the jet(s). Blowing through them is not always effective so you may have to clean them with a soft copper wire (nothing that will scratch them) after soaking in some cleaner. Take care when dismantling not to damage any gaskets or seals, or be prepared to buy new ones, and not to loose any small bits. Also carefully note how it all goes together, especially if you do not have a manual or a diagram. Check carefully for O rings or small washers as you take things apart!
If you cannot sort it out with advice from here then go to the Mercury/ Mariner board on the iBoats forums However if you do go there give the FULL model details.
ArthurWood
Well-Known Member
Had the same prob with my 3.3. There was water in the carb bowl. On mine the drain plug - a small screw - is accessible from under the motor without having to remove any cowling.
misterg
Well-Known Member
[ QUOTE ]
suspeect fuel problem, is there afuel filter I can check on it?
[/ QUOTE ]
I think there is a fuel filter built into the connection at the bottom of the tank:
If the fuel tap is connected to the tank with a short (10mm?) length of hose and a hose clip nearly as big, take this off (as if you were removing the fuel tap) to expose the connection at the base of the tank. On mine there was a small conical filter mesh pushed into the inside of the tank connection, which could be pulled out once all this gubbins was removed.
Once I knew it was there, I could see it through the filling hole (empty tank).
May or may not be your problem, though.....
Andy
suspeect fuel problem, is there afuel filter I can check on it?
[/ QUOTE ]
I think there is a fuel filter built into the connection at the bottom of the tank:
If the fuel tap is connected to the tank with a short (10mm?) length of hose and a hose clip nearly as big, take this off (as if you were removing the fuel tap) to expose the connection at the base of the tank. On mine there was a small conical filter mesh pushed into the inside of the tank connection, which could be pulled out once all this gubbins was removed.
Once I knew it was there, I could see it through the filling hole (empty tank).
May or may not be your problem, though.....
Andy
ShipsWoofy
Well-Known Member
Dan, can we have a 'black border' instant mark up tool please.
jimi
Well-Known Member
Thanks guys for the advice.