Adding fuel cut-off valve

[superbenk]

I have a 5.0L carbed Mercury in a 2008 Four Winns H200 that I'd like to add a shut-off valve to in order to help run the carb dry in the winter & make it easier to change the fuel/water separator filter without dumping gas everywhere. I'm wondering where the best place to run it would be? I'm assuming it'd be best to thread it into the filter manifold before the flexible pickup fuel line?

tank -> flexible fuel hose -> **shut-off valve** -> filter manifold (in) -> filter -> filter manifold (out) -> fuel pump -> carb

 

[Bt Doctur]

Re: Adding fuel cut-off valve

removing the tank fuel line where it connects to the filter port. to have gas leave the filter you have to add air.
But if you were to use a fogging fuel connected to that port and run the engine you wouldnt have to run it dry.

 

[Silvertip]

Re: Adding fuel cut-off valve

Adding fuel treatment like StaBil or SeaFoam and then running the engine until the treated fuel is fully distributed eliminates the need to run the carb dry -- which by the way you cannot do anyway. There will always be some fuel in the bowl. A full bowl has very little air. The less air in the bowl, the less chance for crud build-up. Shutting off the fuel between the tank and filter would not allow the filter to be purged by running the engine. Suck on the soda bottle and see what happens. If air can't get in, fuel can't get out.

 

[Scott Danforth]

Re: Adding fuel cut-off valve

not to mention dead heading the fuel pump suction isnt good for longevity of the fuel pump. put in quality fuel, run a stabilizing agent if you want, complete the rest of the winterization items like lubricants, etc. no need to attempt to run the carb dry.

 

[superbenk]

Re: Adding fuel cut-off valve

Thanks all! Is there a trick to replacing the fuel filter without it spilling gas all over the bilge then?

 

[Bondo]

Re: Adding fuel cut-off valve

Thanks all! Is there a trick to replacing the fuel filter without it spilling gas all over the bilge then?

Ayuh,... There should be an anti-siphon valve on the top of the fuel tank,...

If so, you'll only loose a tiny bit of gas when swappin' filters,....

I crack the filter Just Loose, then slip a freezer baggie 'round it, 'n spin it off, droppin' it into the baggie,...
Zip up the baggie, 'n nearly No fuel is spilt,...

Pull the motor's dipstick to get a little oil for the new filter's o-ring, 'n spin it on,...

 

[superbenk]

Re: Adding fuel cut-off valve

I don't get a lot of fuel, but the filter is totally full & there's some fuel in the lines leading to the pump & manifold that drains out when the filter is removed thus overflowing. Just makes a mess that I'd like to figure out how to avoid if possible. Maybe it's just how it is & I'll have to do the bag trick too.

 

[Silvertip]

Re: Adding fuel cut-off valve

As for how to avoid the mess there are dozens of solutions -- use your imagination. Here are a few ideas:

1) Go to the Dollar Store and buy a small plastic tray or pan that can be placed under the filter.
2) Cut the top off a gallon milk jug to catch the overflow
3) A couple of shop rags (old T-shirts, old towels, etc.) will work. Just don't leave them lay in the garage. Leave them outside until the fuel evaporates out of them.

 

[fen-isl]

Re: Adding fuel cut-off valve

If you have a electric fuel pump just disconnect the wire to the pump start the engine and wait for it to stall out. Carbs been run dry and your able to replace the filter with little mess. Thats how I do mine works great. I also have made a tube that goes into pump outlet and a jumper wire so I can pump the gas tank dry at end of season . Never have a fuel problem and in the spring shes starting on fresh gas!!