Electric Fuel pumps

[terrence]

I wish I could stay on my MB long enough to go through that much fuel. I get to ressless and have to get off and stroll around a few minutes.
I would also use it as a transfer pump only. I tried to use a elec fuel pump on my riding mower and it constantly would flood the bowl.
Maybe you could be the guinny pig for the rest of us? terrence

 

[Tinker1980]

An electric fuel pump could be used without transfer tank, and without flooding the engine. When you get the fuel pump, grab a pressure regulator. U can get an adjustable one, adjustable from full pressure all the way down to 1/2 PSI, in 1/2 psi increments.

You don't have to worry much about the fuel pump pushing the float valve open. Sure, it may be 7 PSI, but the valve is lots less than a square inch.

The other thing nice about the regulator is it comes with different size nipples, so u can go from the 3/8" line at the pump to the smaller line at the carb.

Good luck, can't wait to see your setup!

-Mark

 

[terrence]

An electric fuel pump could be used without transfer tank, and without flooding the engine. When you get the fuel pump, grab a pressure regulator. U can get an adjustable one, adjustable from full pressure all the way down to 1/2 PSI, in 1/2 psi increments.

You don't have to worry much about the fuel pump pushing the float valve open. Sure, it may be 7 PSI, but the valve is lots less than a square inch.

The other thing nice about the regulator is it comes with different size nipples, so u can go from the 3/8" line at the pump to the smaller line at the carb.

Good luck, can't wait to see your setup!

-Mark

Thanks, This is good to know. Could you recomend a supplier? terrence

 

[loquin]

One consideration of the series piping shown in the diagram is the cap of the smaller "standard" tank must be sealed (unvented). Otherwise the tank with the higher head will overflow the lower head tank.

Honda has an arrangement for a couple of their camping generators to run in parallel through a parallel wiring harness.

In order to make this arrangement work more easily, they sell a third tank which has two outlets and these lines connect to each generator replacing the standard vented cap. Then as each generator uses fuel, it is refilled from the larger tank setting above both tanks.

Unfortunately the cap of the China tank doesn't have a top vent hole, so you would have to find a cap that would fit and you could plug the vent.

Jim

Actually, both tanks need to be sealed. The air/excess fuel is drawn through from the carb to the 'far' tank. Fuel is drawn from the 'far' tank to the 'near' tank, and then, on to the carb. If there's an air leak anywhere in the loop, it will short-circuit the loop.

 

[MotorbikeMike]

full-flow fuel system

Hi I did two Gebe's by using the instruction from Gebe. Here is how I did 2 sucessful bikes. Drill a small hole (fitting fuel line tight enough to seal) in the very top of plastic tank on engine.

Mount peanut in normal position, plumb the line down the frame, into the top of the tank inserting it about an inch- to inch and a half. the vented tank is the upper tank so you will not "vaporlock".

Now as the lower tank draws, it continiuosly refills itself from the upper tank, without overflowing anything. The lower tank is never completely full, and that keeps the fuel from even trying to get out of the seal on the plastic tank where the line is inserted.

You fill from the peanut, with loads the complete sysyem.

Here we have engaged your freind "mother nature" to provide the transfer force (gravity) and do not have to mess with fuel-pump, or any thing else.

BTW the little carbs are VERY easy to push past the needle and seat and a pump will surely do that for you, you have just not experianced that yet.

Mike

 

[Terminal Velocity]

If I understand you right, you really haven't increased the effective capacity of the system. If the larger tank is lower than both the carb and top tank, then you'll only get as much fuel "pumped" as there is in the large tank...equation of continuity (Fluid Dynamics 101)...or perhaps I'm misunderstanding. I think a diagram would help me lots!!! BTW, I teach college physics which is why I must be picturing this incorrectly if this is a setup that works

 

[MotorbikeMike]

Gravity Flow System

HI well, I learned a lot of what was needed on the farm. We built, repaired, improved, or just got along as needed.

If the lower tank is ALMOST full, with the filler tube inserted 1" or so into the little top nubbin of the tank, AND you add either .6 gallon (small peanut) or .96 gallon (large peanut)this is pretty good!

I'm figuring the loss on the little goofy weedeater tank at about 2 ounces.

I'm figuring that you are WAY ahead, seeing that the weedeaters only hold 18-32 ounces or so?

The fuel line inserted into the plastic tank does a "fluid-lock" on the filling motion from the upper tank, and is a joy to behold! As you consume fuel, it automaticly refills only that which is used.

Mike

 

[cruiser66]

The Honda clone has a special carb for fuel tanks lower than the carb. I have no idea how to get one, but I think it would also work with the Honda.

http://search.live.com/results.aspx?q=HuaSheng+142FL-AG&go=&form=QBNO

66

 

[jimraysr]

Two tanks

I have seen pumping carbs for 50 years. My uncle held the original patent for them when he got Olson & Rice to upscale their largest model airplane engine for him to power a light weight generator. He was a field surveyor for Peebody Coal Company. It was still the day of vacuum tube equipment.

While these carbs pump fuel, they don't have a return line!

The hockey puck pump supplied with the Honda GXH50 works in a like manor, but uses crank case atmospheric changes as a power source rather than engine intake vacuum.

So while the diagram is interesting, it looks more like a modern auto pump system which has a return line from a pressure regulator or relief valve.

As Honda supplies the pump, it seem obvious that it would be compatable with the limits of the GXH50 carb.

I do think some of the China clone dealers sell pumping carb. and I would also guess it will fit the Honda as they probably also copied the stud spacing that holds the carb. and the air cleaner.

Jim

 

[mechanicojoe]

why dont you use a go kart pump. because when iraced ihad just the gravity fed fueltank on my honda. ithen switched to a pulse pump. it sucks the gas it needs from the vibrations of the engine