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Hunterb
04-04-2006, 02:24 PM
Hi everyone,

I have a question about the small plastic hose that runs from the flame arrestor to the fuel pump on my Ford 351. I want to replace that hose as it is old and brittle looking. What is the purpose of that hose? I realize it is some sort of marine safety design, but what does it do? Is it only air that travels through it? Which direction is the flow, from the flame arrestor to the pump or the other way? :confused:

If you know, and don't mind sharing, I'd like to know.

Thanks

Bruce

TMCNo1
04-04-2006, 02:33 PM
The hose is there in case the fuel pump diaphram starts leaking and instead of the little tube on the side of the fuel pump dumping fuel in the bilge, the fuel is pushed into the tube and up to the carb. Most Home Depot, Lowes, Ace hardware carry that size hose in the clear, but be sure it is gasoline compatible. If you know any go-kart racers or go-cart race supply shops in your area, they have this tubing in stock for fuel and oil lines and they come in the clear colors.

east tx skier
04-04-2006, 02:34 PM
Bruce, I've seen some with the hose and some with it running directly off the carb and nothing attached to the flame arrestor. I'm very interested to see what the answer is to this one.

Hunterb
04-04-2006, 02:43 PM
TMCNo1,

Thanks for the reply. I knew it was a safety feature of some kind but wasn't sure what it's purpose was for sure. I have been looking for the clear line to replace it but haven't been able to find one that is compatible with gasoline. There aren't any go-kart racers around here that I know of but I'm sure I can find the hose somewhere. Is there a reason that it's clear?

Bruce

redmike
04-04-2006, 02:47 PM
it is clear so you can quickly see if there is any gas in it, letting you know the diaphram has ruptured....

east tx skier
04-04-2006, 02:50 PM
Now I have a fuel drain hose that's about 1/4" in diameter on the port side of my carb going back to the fuel pump. (1) Is this the same hose? (2) If yes, does it matter that it's on the carb and not the flame arrestor?

redmike
04-04-2006, 03:06 PM
not sure; never had one that went anywhere but the flame arrestor? Sounds like a vent for one of the carb bowls, but without seein it, not sure, sorry...

Hunterb
04-04-2006, 03:18 PM
East Tx,

If the above posters are correct, and I assume they are, then the hose on your carb is doing the same thing. It's not really a fuel drain hose, but a way of routing fuel away from the bilge in the case of a failed fuel pump. I assume this only happens if the diaphragm is leaking a little bit because if it was leaking a lot, or failed completely, the pump would be unable to push fuel anywhere and the flow would simply stop. I have heard of fuel pump diaphragms failing and allowing fuel to drain into the oil pan, which is not good for the bearings. Your line (East tx), coming from lower on the carb than the flame arrestor may also provide some protection in the reverse situation as well, routing fuel from a severely flooded carb back to the pump, but that seems unlikely.

Onwards and sideways !!

Bruce

HdGPS190
04-04-2006, 03:25 PM
Replaced mine last year and it was a pretty simple task. Got the hose from SkiDIM:

http://www.skidim.com/prodinfo.asp?number=R045029

Just make sure you order enough length of hose. Hope this helps.

east tx skier
04-04-2006, 03:42 PM
East Tx,

If the above posters are correct, and I assume they are, then the hose on your carb is doing the same thing. It's not really a fuel drain hose, but a way of routing fuel away from the bilge in the case of a failed fuel pump. I assume this only happens if the diaphragm is leaking a little bit because if it was leaking a lot, or failed completely, the pump would be unable to push fuel anywhere and the flow would simply stop. I have heard of fuel pump diaphragms failing and allowing fuel to drain into the oil pan, which is not good for the bearings. Your line (East tx), coming from lower on the carb than the flame arrestor may also provide some protection in the reverse situation as well, routing fuel from a severely flooded carb back to the pump, but that seems unlikely.

Onwards and sideways !!

Bruce

My understanding of it was that it was at least doing as much as what the hose from the flame arrestor was supposed to be doing. That has been the opinion of at least two mechanics I've asked about it.

Hunterb
04-04-2006, 04:03 PM
I searched a bit for a supplier of this kind of line. Interestingly the marine supply places in Nanaimo don't stock it. I found it at a small engine repair place. Apparently it is used on lawn-tractors and other small equipment quite commonly. I'll stop in on my way home and pick some up.

Thanks for the info everyone. A couple more weeks of snow skiing then by the middle of May we can start boating around here without looking like idiots.

Bruce

TonyB
04-04-2006, 06:50 PM
Its primary purpose is as a "sight" hose.

If there is gas in that line, you need to replace your fuel pump.

Hunterb
04-05-2006, 01:50 PM
I got the hose yesterday. I couldn't get the totally clear stuff but got some that is see through yellow. I'll be able to see if I've had a pump failure.

Now I have a new hose, and I know what it's for.

Thanks for the replies everyone.

Bruce