facet fuel pumps

[herman pahls]

I am considering removing the stock engine driven fuel pump on my Jabiru and going with gravity fuel flow and using a Facet fuel pump for take off and landing.
I believe the facet fuel pump is used as a back up pump on the Vans RV airplanes.
When the Facet pump is not powered will fuel flow freely and not be a restriction?
Thanks Herman

[ackselle]

Herman,

According to the AS website, "fuel will flow through in the event of a pump failure".... I think that means "yes".

Cheers,
Ackselle

[Jerrytex]

I have this same setup on my plane and the fuel flows through the pump with no issues when the pump is off. It is only used on Takeoff and landing or as a backup in case the engine driven pump quits. They are rather loud too.

[avidflyer]

I also removed my mechanical fuel pump and now have an electric fuel pump on my Jabiru powered Avid MK IV. I still have the stock 2.5 MM seat for the float needle. I've been meaning to put the 3.7 MM seat in but have yet to order it from Bing Carbs. I use my electric fuel pump for full throttel operations, but have been told that if I put the 3.7 MM seat in, I will not need the fuel pump as the larger seat will flow enough fuel to run the engine at full throttel. The reason I got rid of the mechanical fuel pump is because it was putting out too much pressure and flooding the engine when I pulled the throttel back to idle when comming in to land. I don't use the electric fuel pump for landing. (Had to come back and add this) The pump does not act as a restriction in the line, fuel will flow freely through it when it isn't running. Take care, Jim Chuk

[DesertFox4]

I have a back up Facet fuel pump between my header tank and engine fuel pump. I did a flow test before first engine start to confirm its "flow through" capability. It did not restrict gravity flow rates when turned off.

Please do a flow check on any electric pump you may add to your system before flight just in case there has been a design change or in case you got a defective pump and it does not allow free flow when in the off position.

[herman pahls]

I appreciate the replys and the advice to check the pumps flow when not in use.
I was told the stock Jabiru fuel pump will freely flow fuel with gravity.
My pump does not, maybe because my Kitfox has a 8 gallon cowl tank and does not have as much gravity as wing tanks with and a header tank.
I will order a 3.7 needle and seat.
I am considering removing the stock pump and going with gravity with the Facet as a back-up for take off, steep climbs and landing.

Does this forum feel there would be enough gravity from a cowl tank that at the lowest fuel level would only be 8 inches above the carb inlet at level flight?
I am considering using a fuel pressure gauge to confirm that the facet pump is functioning.
Thanks Herman

[avidflyer]

Don't know what to tell you on the gravity feed with the low tank, I guess you will just have to do flow tests to find out for sure. When I went to the faucet pump and got rid of the engine driven pump, the origanial pump was putting out to much pressure and flooding the engine when pulled back to idle. Found out that the Avid doesn't glide as far as I thought with the engine out. Landed on a frozen lake with no problems, but at least I can now say I've experienced a for real engine out at 1000'. Take care, Jim Chuk

[herman pahls]

Jim
I experienced my first for real engine out (Jabiru 80 hp) last Friday after 34 years and 16 years in the Kitfox(Jabiru for 3 years).
Fortunately I was at 1500 feet AGL and found the perfect cow pasture.
I tried restarting once and it ran for a second, then I decided to concentrate getting it down.
I wish I had run out of gas so the mystery would be solved.
Unfortunately running out of fuel looks bad to the FAA and the news.
After trailering the Kitfox back to the airport it started right up and ran great. I did not fly it.
I put a pressure gage after the stock Jabiru mechanical fuel pump and it read 3 pounds. (Jim; my fuel pump also flooded the carb until Jabiru Pacific sent me a fuel pump rebuild kit that reduces the pressure).
The fuel filter and gasculator flowed 10 gals/hour with gavity with 1/4 inch lines.
I found that my mechanical Jabiru pump does no flow at all with gravity from a cowl tank. I need see if it will flow with more gravity.
My wing tank only transfers fuel to the cowl tank so no increase in gravity like normal wing tanks would have.
My cowl tank for years has been vented to the top of the wing tank which means that when the wing tank is full, fuel will go down the vent line.
Would this fuel cause a venting blockage??
Do most Kitfox's have there collector tank vented this way?
The wing tank has a filler cap with the 90 degree bent tube into the airstream.
Maybe the vent tube got pinched when folding the wings out for flight which I do every time I fly. I do not see how it could be pinched.
I have carb heat to the 40mm Bing carb but was not using it when engine quit.
There did not seem to be a reduction in RPM to indicate carb ice or would the constant velocity nature of the Bing mask ice restriction to a point.
Since the dead stick landing.
I have increased all the fuel lines to 3/8's.
I will install a 3.7 Bing needle and seat.
I have installed a facet 3-4 PSI pump after the gasculator.
I want to see if the facet pump will pump thru the stock Jabiru pump.
If not, I see the Jabiru pump as a liability.
If I had true wing tanks I would go with gravity only, not use the mechanical pump and maybe use the facet as a back-up.
I hesitate flying without a reason for the engine out.
Any ideas or suggestions.
Thanks Herman

[avidflyer]

When I first had problems with my engine I had about 350 hrs on it. It ran fine at full throttel and cruise, but when I pulled the power to come in to land, it died. Don't know why it never gave problems earlier but it didn't. I had landed on a frozen lake, (I fly on skis in winter) and had shut down and when I went to start it about 10 minutes later, it fired up, then died and then wouldn't start. When I had almost run the battery dead, it finally fired up. I flew around the lake a few times and it seemed okey, so I headed for home. I was comming in to land and when I pulled the throttel back to idle, it died. At first I thought I was going to have to land in the neighbor's field cause I was just a bit low to clear the trees at the edge of my field. I worked the throttel in and out, and it caught again and I made it over the trees and landed on my strip. It died again when I cut the power. In searching for the cause, I talked to Bing carb and described some of the symtoms. If for instance, I would idle the engine, when I shut it down, fuel would run out of the throat of the carb. Anyway, the first thing the guy at Bing said was you have to much fuel pressure. I tried all kinds of other things, Was flying with a new carb when I had the engine out where I landed on the lake. In the end, I got rid of the original fuel pump and went with a 1 1/2 - 2 1/2 lb faucet fuel pump. No problems since, the only time I use the pump is for full throttel operation. I would be worrying about over pressure with a 2 - 4 lb pump, especially when pulled back to idle as it it very easy to overpower the float needle valve and seat and the fuel level will get to high in the float bowl and it will flood the engine. I could get fuel running out of the carb when it was showing 3 lbs of fuel pressure in the fuel line. I really should get around to putting in the 3.7 MM seat from Bing, then I should be able to get rid of the pump for good, or just keep if for standby. Speaking of the 3.7 MM seat, if you are pushing fuel at 4 lbs of pressure, you are much more likly to overpower the needle valve than with the stock 2.5 MM seat. I guess what I'm trying to say, is I wouldn't go with that bigger fuel pump, as I think that 2 1/2 lbs of pressure is almost more than enough to overpower the 2.5 MM seat. Hope I haven't confused the issue worse for you. Give the guy at Bing a call, he is very helpfull and willing to talk. Take care, Jim Chuk

[avidflyer]

Herman, I can't seem to find your phone #, I know I had it when we talked months ago, if you want to give me a call, we can talk easier than type. 218-254-2404 Take care, Jim Chuk