vent in outboard motor tank
MikeFarmer1000
another question... I have a Honda outboard, with a Honda 3 gallon(ish) remote
fuel tank. It has a fuel filler cap with a screw down vent.
The manual I have (thanks to previous advice!) says when filling, to open the
vent before removing the cap, and then close it again to put the tank back in
the boat. It doesn't say whether I should run the engine with the vent open or
closed. I assume if you have to open it, then it must have to be closed???
That sounds odd, as I would have thought a vacuum builds up as the fuel is
used, unless there is some sort of secondary venting..
Any ideas?
Thanks
Mark and Sara
will be overworked and eventually the diaphragm will split.
also, if you leave the fuel line connected to the engine its best to leave
the vent undone as pressure in the fuel tank can cause the fuel pump
diaphragm to split (make sure the area arount the tank is well vented)
Mark Harris
L R Harris & Son
"MikeFarmer1000" <mikefar...@aol.com> wrote in message
news:20041102084948...@mb-m16.aol.com...
Jim Riley
"Mark and Sara" <del...@harris1971.freeserve.co.uk> wrote in message
news:cm8nns$i2k$1...@newsg1.svr.pol.co.uk...
> when running the engine always undo the tank vent or the engines fuel pump
> will be overworked and eventually the diaphragm will split.
>
> also, if you leave the fuel line connected to the engine its best to leave
> the vent undone as pressure in the fuel tank can cause the fuel pump
> diaphragm to split (make sure the area arount the tank is well vented)
>
I find the engine stalls when I 've forgotten to open it, but don't know
how long the pump has been struggling for at that point. One tends not to
forget again after it's happened on a river!
Jim
CC Juno
MikeFarmer1000
>> will be overworked and eventually the diaphragm will split.
>>
>> also, if you leave the fuel line connected to the engine its best to leave
>> the vent undone as pressure in the fuel tank can cause the fuel pump
>> diaphragm to split (make sure the area arount the tank is well vented)
>>
>
> I find the engine stalls when I 've forgotten to open it, but don't know
>how long the pump has been struggling for at that point. One tends not to
>forget again after it's happened on a river!
>
>Jim
>CC Juno
>
open, so thats how I've left it. It probably should be closed when unattended,
but like Jim, I'm afraid of leaving it closed when I start off.
I think I can feel a pre-sailing checklist coming on!
Peter Stockdale
"Jim Riley" <jimne...@tiscali.co.uk> wrote in message
news:4187f6a2$1...@mk-nntp-2.news.uk.tiscali.com...
>
Yes - I believe it is some sort of nips revenge for them being beat in the
war - they are getting their own back on us by missing out pertinent details
in their pigeon English manuals.
I have numerous examples in my iseki manual.
Pete
Graham Bowers (Zen)
>
> Yes - I believe it is some sort of nips revenge for them being beat in the
> war - they are getting their own back on us by missing out pertinent details
> in their pigeon English manuals.
> I have numerous examples in my iseki manual.
>
> Pete
>
>
Don't mention the w*r
Graham
klog
[snip]
> Thanks guys. I must admit I couldn't see how it would work unless the
vent was
> open, so thats how I've left it. It probably should be closed when
unattended,
> but like Jim, I'm afraid of leaving it closed when I start off.
> I think I can feel a pre-sailing checklist coming on!
errr.... my understanding of the whole idea of having a vent that can
be closed is simply to allow transportation without spillage.
If you *do* leave the vent closed when unattended in the summer
(remember that?), you'll find that your tank takes on an interesting
(and dangerous) shape!
Best leave it open unless transporting (and even then, be careful about
expansion). Of course, to comply with the BSS, you aren't really going
to leave it in the boat unless in a suitable enclosure or outside the
cabin/cockpit, are you?
MikeFarmer1000
>errr.... my understanding of the whole idea of having a vent that can
>be closed is simply to allow transportation without spillage.
>
>If you *do* leave the vent closed when unattended in the summer
>(remember that?), you'll find that your tank takes on an interesting
>(and dangerous) shape!
>
>Best leave it open unless transporting (and even then, be careful about
>expansion). Of course, to comply with the BSS, you aren't really going
>to leave it in the boat unless in a suitable enclosure or outside the
>cabin/cockpit, are you?
>
of, the confusion I had was over whether or not I should run the engine with it
closed.
The tank is a sturdy metal Honda issue, so if it does distort, I should think
it would be ready to take out the whole marina :-)
It does sit in its own purpose made section of the hull, away from any other
bit of kit, including batteries and the like. The enclosure is vented and
insulated as far as possible, and I do check for leaks and vapours on a regular
basis.
I'm sure it must comply because I can't imagine there are any other precautions
that could be taken.
Tony Clayton
I used two separate tanks to avoid carrying spare fuel in an ordinary can.
The old tank (from my long derelict Honda 7.5) had a plastic pointer on the top
of the filler, which long since failed to seal. The other more
modern one from my Honda 15 had a metal screw vent which could be the devil
to undo.
The purpose is to keep the fuel at atmospheric pressure when open, and
prevent spillage when tranporting the can when closed.
Leaving it open when carrying it meant that fuel spilt onto the outside
of the can. Avoid going near smokers if this happens.
Leaving it closed when using the engine rapidly resulted in the engine
stopping as the lower pressure as the tank emptied prevented the fuel
reaching the engine. This is embarassing when you are trying to leave
a Thames lock or when passing the upstream end of an open weir sluice.
I found that the best way of getting two heavy cans to and from
a petrol station was to use my wife's wheelchair (without her being
in it - I quickly learnt that she did not appreciate fuel spilling
over her clothes if I forgot to seal the vent...) ;-)
At least it was better than trying to carry my old Crescent 5
gallon can, which was very heavy.
--
Tony Clayton tony.cla...@pem.cam.ac.uk or to...@tclayton.demon.co.uk
Coins of the UK : http://www.tclayton.demon.co.uk/coins.html
Values of Coins of the UK : http://www.tclayton.demon.co.uk/values/coins.html
Metals used in Coins : http://www.tclayton.demon.co.uk/metal.html
Sent using RISC OS on an Acorn Strong Arm RiscPC
... A single fact can spoil a good argument.
dadse...@outlook.com.au
Geoff Ellis
> Hi, I have a fairly new 40hp Suzuki 4 stroke on my tinny and I have had issues with the revs dropping to an idle speed from full speed as I’m going along, it will then jump back to top speed after a minute or so, could this be from my vent on my fuel tank being closed.
>
sucked up and blocks the jet, engine goes to idle (different jet}, crud
drops off jet, engine speeds up, rinse and repeat
