Is there such a thing as a hand cranked fuel pump that will operate more than a couple months before it leaks??
I have experience with MK and Horizon. All leaked;some went several months,others maybe a month.
The pumping unit in these two brands are practically identical,so I imagine other brands would not be much,if any better. Others probably have the same unit.
Any suggestions??
BTW I never had a non-leak electric pump either!

Dave

My Dave Brown 6 Shooter doesn't leak.
JLK

I forgot to mention the Dave Brown Six Shooter. I had one of those and I would hate to fill a 20 oz.tank with one.

Dave

Try a MPI hand crank. I've had one for over a year and it cranks so much smoother than the Dave Brown 6 shooter.

BBM

OH Yeah - Six Shooter - the only way to go.
I've just replace the first tube in one of ours after 2 years (with at least 1 gallon per week through it in that time) and even then, that was only because one of the teenagers accidentaly put Gasoline through one set up for Nitro Fuel then left the Gasoline in it.

Agreed re the six shooter--except that on my second one,I mounted it on the outside of my hundred-year old wooden flight box,then wiped off the crank handle on the car door frame in no time....
But real modellers have cunning plans....I just persist with leaky free-floating hand pumps until they become so painfully slow that someone can't stand it any longer, and presents me with a new one...
It's worked twice up to now...

Hi Dave!

If you open your hand crank pump assembly, you will see gears and the actual pump. The pump contains a small impeller, plate cover and a "flimsy" gasket. Open the pump and coat the gasket with silicon RTV. Give it time to dry before you use it.

The leak will reduce your pumping capacity, thus making filling slow.

Goodluck!

there is also an adjustment screw for the diaphram to adjust your pump, usually hidden behind a sticker on the case works great when adjusted properly.

Dave,
There are a couple guys here in District 5 that I have seen with these:
http://www2.towerhobbies.com/cgi-bin...5&I=LXFH66&P=K
Kinda pricey but very nice.
I don't have one but maybe someday...
They are supposed to be very durable.
JLK

Thinking back a few lifetimes, the most hassle-free pump I ever had was an enormous veterinary syringe, 250 ml from memory.
Worked great until someone's car reversed over it.

in my oppinion.... just get used to it!, every pump leaks... in my case I choose the fastest one so at least spent less time and effort re-fueling

As someone said earlier,his six shooter doesn't leak. So I have bolted one firmly to my fuel caddy and am off to the field for a few flights.
I don't really care for the six shooter,but if it doesn't leak,I will learn to love it!

the six shooter doesnt leak ...but it take all day to fill 0,5 liter into the tank ...and my arm is alomst off when the job is done!

The problem with all cranked pumps (except the six shooter) is the seal on the impeller shaft. The faster you turn the handle to fill your tank the more likely the fuel will pass this seal, due to the build up of pressure inside the pump and particularly so if you are using small bore fuel tubing in your model.

I am now using a MK electric pump which I assume is designed to work at the speed the four AA cells will provide and therefore not over pressure the pump unit. Not the fastest I have used, but it has not leaked so far, around 30 Gallons of Cool Power in 9 months, including draining the tank at the end of each flying session.

Or in the tubing to and from the pump----another thing to check is the filter in the tube that goes to the bottom of the fuel bottle(you do have one there, don't you?) clearing the bits out now and again improves the filling time no end!

Re the six-shooter:

Since I took up RC I've gained 5 lbs. So maybe a little exercise is a good thing.

Cycle tire pump and a YS NRV.

A few pumps to pressurise the jug and you can sit back and watch the fuel fill the tank. Magic!

Same system can be used in reverse to pressurise the tank and empty the contents back to the jug.

No more worries about seals and batteries.

Cheap, simple and foolproof.

AA

Almost foolproof, Adrian.
I can demonstrate flaws in any system, being the World Champion Dope.

I have a 5 year old MK hand pump. I was having trouble with engines and fuel pumps years ago. I switched fuels to Cool Power and both problems went away.

I could get about 3 months on a fuel pump using Magnum Fuels and the pump would leak and sometimes even lock up. I switched to Cool Power and the same pumps that would leak and malfunction have now been good. The MK hand pump is excellent. What fuel are you using?

Allen

That's interesting, when I fly glo, Magnum is all I use. Same MK hand pump you are using, 4 years of pumping Magnum 15% and #1 thru it and still going strong. Wonder what is different?
Woodie

Just returned from the field. I am happy to report that my six shooter didn't leak and it takes 87 turns to fill a 20 ounce Dubro tank. My flying buddy has a Cermark and it requires 94 smooth turns to fill 20 ounces. This Cermark has several leak free gallons through it. His previous one leaked like a sieve after several months.
The six shooter,even when sturdily mounted does give one's shoulder and arm a workout,but is well worth it to get rid of the leaks.

I have used nothing but Cool Power for many years.

Dave

Hey Dave!
We are on about the same track.
My 6 Shooter takes roughly 60 cycles to fill 16 oz.
JLK

For 20 oz tank, cycle pump needs 6 to 10 strokes max depending on whether the jug is full or nearly empty.

You guys must be long on dollars and short on excercise!

AA

I have received some private messages asking me to explain the cycle pump set up in a little more detail. For those interested it is really very simple:

2 bulkhead fittings in the cap of the fuel jug. Fitting A terminates just inside the cap and connects into the vapour space above the fuel level in the jug. Fitting B connects to a clunk line running to the bottom of the jug.

The air delivery line from the cycle tire pump connects via a non return valve (NRV) to fitting A – I have used a YS NRV for convenience and because I know that the internal disc will stand up to high nitro fuel. (In practice it only comes into contact with fuel vapour). Fitting B is connected to a short length of fuel tubing in which I have included a small clip that can be used to isolate the line while the fuel jug is being pressurised and after the tank in the model has been filled.

A few strokes of the cycle pump are enough to pressurise the fuel jug. When the jug is full, about 5 or 6 strokes will do the trick, depending on the swept volume of the cycle pump. It will take a few more strokes as the jug becomes empty because of the larger volume of vapour space above the fuel. Once the jug is pressurised, connect the fill line from the jug to the fill line on the model. Open the clip in the delivery line from the jug and sit back and wait for the tank to fill.

The burst pressure of fuel jugs is well above the pressure needed to “blow” fuel from the jug into the tank. However, as a precaution, I depressurise the jug after the tank in the model is full. The application of common sense should tell users if too much pressure is being applied, as the shape of the fuel jug will become excessively distorted. If you feel you can’t rely on common sense, fit a small relief valve to the jug!

The same set up can be used in reverse to pressurise the tank in the model and drain any fuel back into the jug. No moving parts come into contact with liquid fuel and I have used the system successfully with both gasoline and nitrated methanol.

AA

MK electric pump for me. Been using it the last 2 years with no hitch.