Fuel hose clamps

[Justmeagain]

I refitted the fuel system under the deck and under the enclosed stern to include a new external fuel filter bracket and filter, Yamaha sending unit and new fuel lines. The new fuel filter bracket is not steel but a poly type product. The one it replaced corroded under the seal.
The good folks in this community directed me to look for loose or poorly installed hoses and clamps. I tightened them up and that fixed it. 6 to 8 months later we took the boat out for a hard run. it was initially sluggish but did smooth out. After the runs, we motored back to the house and the engine just died at idle speed. Good Samaritan gave us a tow home.
Fuel was good and clean, but what we did find was most of the hose clamps were only snug to loose. I tightened them back then.
Question: Is it possible the clamps can loosen? I'm using correctly sized SS clamps that are a worm type on a 13/16 OD fuel hose.

[99yam40]

probably the hose squeezed out away from the clamp

[fairdeal]

some polymers exhibit "creep" aka "cold flow" when pressure is applied
"rubber" fuel line, not so much

in my experience, properly selecting the hose and hose connectors
results in the hose having to be stretched/forced over barbed connections -

the inherent elasticity of the rubber tubing ensures a good seal

the function of the clamp is to prevent the hose from slipping off while under pressure

so - IMO - if you need the clamp to compress the ID of the tubing, to match the OD of the fitting it is attached to -

you've got the wrong size fittings or the wrong size hose

[panasonic]

some polymers exhibit "creep" aka "cold flow" when pressure is applied
"rubber" fuel line, not so much

in my experience, properly selecting the hose and hose connectors
results in the hose having to be stretched/forced over barbed connections -

the inherent elasticity of the rubber tubing ensures a good seal

the function of the clamp is to prevent the hose from slipping off while under pressure

so - IMO - if you need the clamp to compress the ID of the tubing, to match the OD of the fitting it is attached to -

you've got the wrong size fittings or the wrong size hose

My thoughts exactly....clamps on a low pressure system are just there to keep the hose from slipping back. I would look at the hose size, materail of hose used and size of fittings they are put on....

[Justmeagain]

Hose clamp

The fuel hose is the same ID as the original, new hose is rated Ethanol tolerant unlike the old hose. The barb fittings are 3/8 ID. It was just curious that the clamps were looser.
I wonder if the composite head is a problem. Has anyone heard of these warping and not providing a flat, level surface for the filter/head interface? I can not find a reference on Google.

[robert graham]

The Walmart/Atwood filter has an aluminum body....$28 at Walmart....maybe just change it out from the composite unit?...

[throrope]

Likely the fuel hose got loose, not the clamp, which is a tattle tale of degradation from our lovely ethanol fuels. If the hose is 5 years old or you do not know, I suggest replacing all from tank to outboard, which is cheaper than a failed trip. The clutter and goo from degraded hose can wreak havoc on a fuel system.

Ethanol likes to maintain 5% water which is why grain alcohol is 190 proof or 95%. The ethanol in fuel is processed to eliminate that 5%, but it then has an affinity to water and can pull that desired 5% from humidity. This can lead to phase separation, which is when ethanol falls out of the gasoline, sits at the bottom of the tank and exposes materials rated for E10 (10% ethanol) to much greater concentrations.

I replaced the long lengths from the under the console to the filter and stern with 3/8" soft copper and only use short lengths of hose at the tank and outboard to make replacement cheap and easy.