Slightly off topic - fuel flow and hose diameters

[JohnOrrett]

Hi all. Brother in law's 130BETO has a 2 Yamaha 25L fuel tanks both obviously with Yamaha connectors, so we can switch easily from one to the other.

He has just bought a 5hp Honda auxiliary which has no tank, just the hose connector. He doesn't want to buy a dedicated Honda fuel tank, as hopefully it will be used very rarely, and don't want the fuel going off etc. We want to buy a Honda hose and bulb with both engine and tank connectors and cut off the Honda tank connector and fit a Yamaha, so it fits both existing fuel tanks No mixing required, so just pure fuel in the tanks. Yam is auto lube and Honda is 4 stroke.

Question is, if the hoses are different diameter, will that affect the fuel flow rate into the Honda if the Yamaha is a bigger diameter hose, and flood the engine?

Hope that's not a daft question!

Thanks,

John

[boscoe99]

A bigger hose will not affect fuel flow. Could be a three inch ID hose. The engine will only draw what it needs to draw.

A smaller hose however can adversely affect fuel flow.

[JohnOrrett]

Thanks Boscoe, much appreciated as ever

[DennisG01]

A bigger hose will not affect fuel flow. Could be a three inch ID hose. The engine will only draw what it needs to draw.

A smaller hose however can adversely affect fuel flow.

Agree with the hose ID's not mattering if you're going to a size bigger.

But... and I know you were just making a point...

"IF" someone did use a 3" hose on an engine this size engine... would it actually be able to draw that weight of fuel? It would still need to hold that volume of fuel in the line, up to the engine, right?

[boscoe99]

Agree with the hose ID's not mattering if you're going to a size bigger.

But... and I know you were just making a point...

"IF" someone did use a 3" hose on an engine this size engine... would it actually be able to draw that weight of fuel? It would still need to hold that volume of fuel in the line, up to the engine, right?

Good point. You bees thinking.

Now if one considers that the pump on an outboard motor does not really draw fuel I think that the size of the hose would not matter technically. The pump lowers the pressure at the inlet to the pump. The air pressure, being greater than the lowered fuel pressure at the pump inlet, pushes the fuel towards the pump.

Now a problem might be that long before the air pressure could respond to the lowered air pressure and push enough fuel to the pump, having to fill the fuel hose in the process, the motor would die due to fuel starvation. It only has so much fuel to work with before it has to be resupplied by the pump.

I did use an exaggerated fuel hose size for illustrative purposes. Practically speaking though that big of a fuel hose would not work.

Does an electrical load device draw electrons from a battery or does a battery push electrons to and through the load device? Do those electrons flow more or less freely as the size of the hose (the wire) is increased? Can the size of the wire be so big that it cannot fill up with electrons before the device load stops drawing electrons?

[DennisG01]

Yes, I guess I used that word "draw" in a general sense - but what you said makes sense... positive vs negative pressure, etc.

Oh, man, now you got me thinking about electricity! But, YES! Electrons actually flow from the neg to pos. I'm not quite sure if the pos side pulls them or if the neg side pushes. I've never thought about it that way - just in terms of "flowing".

I would guess "no", there's no such thing as a wire being too big causing a detrimental effect... other than my wallet, weight or the ability to "work with it".

Too small, sure, of course. But then I suppose we also need to clarify if we're actually discussing volts or are we talking amps?

FYI, I can only go so far with this discussion before I have to start googling!

[tmann45]

Now a problem might be that long before the air pressure could respond to the lowered air pressure and push enough fuel to the pump, having to fill the fuel hose in the process, the motor would die due to fuel starvation. It only has so much fuel to work with before it has to be resupplied by the pump.

I did use an exaggerated fuel hose size for illustrative purposes. Practically speaking though that big of a fuel hose would not work.
I don't see why not, only the fuel used has to be resupplied. Hose size only makes a difference if too small for flow.

Does an electrical load device draw electrons from a battery or does a battery push electrons to and through the load device?
Battery pushes or pulls, take your choice, the load device does neither.

Do those electrons flow more or less freely as the size of the hose (the wire) is increased?
More freely if the wire was too small to begin with.

Can the size of the wire be so big that it cannot fill up with electrons before the device load stops drawing electrons?
NO

That's my story and I'm sticking to it until you prove differently http://www.yamahaoutboardparts.com/i...ons/icon10.gif

[JohnOrrett]

Stop it, you are all making my brain hurt! :-)

[boscoe99]

Stop it, you are all making my brain hurt! :-)

Was the question about fuel flow in imperial gallons or US gallons? Is the hose ID in SI or "merican english?

[TownsendsFJR1300]

Ethanol or non-ethanol?

And if its high test, you need less fuel...

[zenoahphobic]

Ethanol or non-ethanol?

And if its high test, you need less fuel...

The OP worried he was daft. He proved some of you are.

Pressure or vacuum (suction) due to gravity has absolutely nothing to do with the volume or diameter of the hose!! It is just shear height. Go back to school.

Sorry didn't intend this to quote person above.

And the electricity understanding is even worse.

[zenoahphobic]

Simply, one essential difference between a liquid flow and electricity flow is that in an electric current the individual electrons get equally excited and jump from molecule to molecule at a constant speed (speed of light) irrespective of the conductor size. In a liquid it is the molecular bond that holds the molecules together so when there is pressure or gravity exerted the molecules "follow" (syphoning effect) each other (within limits) at the rate of the force and conductor size.

[zenoahphobic]

Some of you like your "pressure" and "less pressure" "not vacuum" theory.
How do you pump fuel in space, i.e. in the absence of air pressure? Is it possible?
Think about what happens with the simple child's bubble making machines. What makes the bubble?

[TownsendsFJR1300]

The OP worried he was daft. He proved some of you are.
.

It was a JOKE..............

[99yam40]

Simply, one essential difference between a liquid flow and electricity flow is that in an electric current the individual electrons get equally excited and jump from molecule to molecule at a constant speed (speed of light) irrespective of the conductor size. In a liquid it is the molecular bond that holds the molecules together so when there is pressure or gravity exerted the molecules "follow" (syphoning effect) each other (within limits) at the rate of the force and conductor size.

In respect to the similarities of a liquid or even a gas and electricity flow, they talk about how smaller wires or smaller pipes cause more resistance to the flow, larger = less resistance.
there are plenty of differences