"il_papa" wrote in message
oups.com...
My first post here .. I launched my boat today after the long danish
winter, to experience problems with my four-stroke 4HP Mariner
Outboard. The motor started fine (only 4 - 5 attempts) For some reason
or other the motor cuts out after a few minutes, and I have a feeling
that there is something up with the fuel supply. I have an external
fuel tank which is positioned below the motor's fuel inlet, so the
fuel hose has to travel up before being lead through the transom and
into the motor .... could this possible cause the problem, i.e. a fuel
syphon problem, is there a maximum fuel hose length (mine is probably
about 2m long? The motor will start again after 30 seconds or so after
I have pumped more fuel to the motor and given it some choke. Any help
appreciated.


Check the vent on the remote tank. Oftentimes after a storage episode
the rubber grommet in the vent in the fuel tank cap becomes squashed and
collapsed so even if it's in the open position it fails to allow air
into the tank and a vacuum develops. Try running the engine with the
fuel fill cap loose at the threads to see if the problem stops. If so
troubleshoot the vent mechanism or purchase a new cap.

Wilbur Hubbard

On 2007-04-15 15:19:00 -0400, "Wilbur Hubbard"
said:

"il_papa" wrote in message
oups.com...
My first post here .. I launched my boat today after the long danish
winter, to experience problems with my four-stroke 4HP Mariner
Outboard. The motor started fine (only 4 - 5 attempts) For some reason
or other the motor cuts out after a few minutes, and I have a feeling
that there is something up with the fuel supply. I have an external
fuel tank which is positioned below the motor's fuel inlet, so the
fuel hose has to travel up before being lead through the transom and
into the motor .... could this possible cause the problem, i.e. a fuel
syphon problem, is there a maximum fuel hose length (mine is probably
about 2m long? The motor will start again after 30 seconds or so after
I have pumped more fuel to the motor and given it some choke. Any help
appreciated.


Check the vent on the remote tank. Oftentimes after a storage episode
the rubber grommet in the vent in the fuel tank cap becomes squashed
and collapsed so even if it's in the open position it fails to allow
air into the tank and a vacuum develops. Try running the engine with
the fuel fill cap loose at the threads to see if the problem stops. If
so troubleshoot the vent mechanism or purchase a new cap.

Wilbur Hubbard

Agreement. That's the most usual suspect of that sort of behavior. Pump
the priming bulb and see if it's still "hard". (If not, look for a bad
connection in the hose.) After that, I'd check the bowl & float for
gunk, possibly rebuild the carb if you have any doubts.

Another thing that sometimes causes intermittent problems is the kill
switch. You might also have a switch at the fuel connector. Sometimes
vibrations will cause either to turn the engine off. Pull the plug and
lay it on the head to see if you're getting spark. At the same time,
you might smell/see if you're getting fuel.

--
Jere Lull
Tanzer 28 #4 out of Tolchester, MD
Xan's new pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI pages: http://homepage.mac.com/jerelull/BVI/

Thanks for the advice ... the fuel tank cap vent sounds like a
distinct possibility, so I'll check that out. I should possibly
explain what is happening a bit more accurately. The motor's rev level
becomes unsteady and becomes a mixture of slowing and or misfiring,
and then cuts out. Its not like it happens all of a sudden, and I can
tell when it is going to cut out, but I don't seem to be able to stop
it happening ... seems to happen at the worst possible times too...