Backup fuel pump?

[coen]

Need information on how to add a backup electrical fuel pump to the existing fuel supply on a microlight(582/503) .Contemplating an additional fuel fiter in a parralel configuration. I need some advice on wether it is viable proposition. Any sugestions will be appreciated.

Many thanks Coen.

[Morph]

Discussed in great detail here

viewtopic.php?f=13&t=309

In short, install it in series, not parallel. The pump does not have a one way valve. If installed in parallel then you could get fuel flowing back through the spare pump, reducing fuel pressure and resulting in problems

[Wargames]

Discussed in great detail here

viewtopic.php?f=13&t=309

In short, install it in series, not parallel. The pump does not have a one way valve. If installed in parallel then you could get fuel flowing back through the spare pump, reducing fuel pressure and resulting in problems

What is the appr. price of the facet pump??

Another advantige of a pump is that when your system is presurised, you can see leaks, that would other have the ability to suck air into system.

Regards,

[Morph]

I believe they are around R400 now. Definately worth the investment, believe me.

[cjkrit]

I do not want to cause any confusion but it is stated on www.ultralightnews.com that such a pump be in parallel. Quote: If an electric pump is to be installed run the pump in a parallel configuration with the fuel pickup prior to the vacuum pump and inserted back into the system, after the pump. Make sure that the electric pump you select does not put out more pressure than is recommended or you could cause your carbs to fail.
I have read that in serie if the backup pump is not operated it could cause some resistance to the fuel passing through it. Is this only used for take-off and landings or is it left on all the time? Purchased one this morning and this one allows no backflow of fuel- some type one-way valve. If switched off it wil not allow flow in opposite direction.
We need more clarity on this. Comments?

Christo

[Arnulf]

I do not want to cause any confusion but it is stated on http://www.ultralightnews.com that such a pump be in parallel. Quote: If an electric pump is to be installed run the pump in a parallel configuration with the fuel pickup prior to the vacuum pump and inserted back into the system, after the pump. Make sure that the electric pump you select does not put out more pressure than is recommended or you could cause your carbs to fail.
I have read that in serie if the backup pump is not operated it could cause some resistance to the fuel passing through it. Is this only used for take-off and landings or is it left on all the time? Purchased one this morning and this one allows no backflow of fuel- some type one-way valve. If switched off it wil not allow flow in opposite direction. We need more clarity on this. Comments?

Christo

Hi Christo,

which pump did you buy?
I would also prefer a parallel installation, however does your engine driven pump have a non return valve? Other wise you might have a problem that the electrical pump does not deliver enough fuel to your carbs. Just wondering

Regards,
Arnulf

[cjkrit]

I listen to what you say- The pump is a no-name brand- this one has a non-return valve. Seems like the Facet pump is the one to go for. No valves will cause least resistance to flow if pump is switched off. The parallel installation seems to complicate matters. I do not have so much knowledge of the Mikuni pump on my 582, whether non-return or not, I really don't know.
The postings on this forum tell of guys who has the serial installation for long time, and it works well.

[John Young]

However does your engine driven pump have a non return valve? Other wise you might have a problem that the electrical pump does not deliver enough fuel to your carbs. Just wondering.

Hi,

On the 582, I suspect that Christo has the standard diaphragm pump - meaning that one or both butterflies will always be open to allow fuel through.

The in series installation is fine using the tank – facet – filter – diaphragm pump configuration.

A parallel installation certainly requires a lot of extra plumbing. I have a parallel configuration on my trike, meaning two pick-up lines, two filters, two ‘T’ pieces allowing the carburettors to be independently fed by either of the facet or mechanical pump systems.

I listen to what you say- The pump is a no-name brand- this one has a non-return valve. Seems like the Facet pump is the one to go for.

Hi Christo,

It is very important to have a facet pump that does not deliver more than 3 psi. Some facet pumps are capable of delivering a much higher pressure which will cause damage to the needle and seat (very expensive and dangerous).

Here is another link - unfortunately the punctuation got a bit messed up when Microlighters changed over to this software.

viewtopic.php?t=3840&postdays=0&postorder=asc&start=0

Regards
John

[Duck Rogers]

A parallel installation certainly requires a lot of extra plumbing. I have a parallel configuration on my trike, meaning two pick-up lines, two filters, two ‘T’ pieces allowing the carburettors to be independently fed by either of the facet or mechanical pump systems.

And that's the way I believe it should be.

[Wargames]

A parallel installation certainly requires a lot of extra plumbing. I have a parallel configuration on my trike, meaning two pick-up lines, two filters, two ‘T’ pieces allowing the carburettors to be independently fed by either of the facet or mechanical pump systems.

And that's the way I believe it should be.

Hi oom Duckie,

Care to share your views as to why you would suggest a paralel instalation. I did a serial instalation this weekend. My instalation is Fuel tank -> filter -> facet -> fuel flow sensor -> machnical pump -> carbs. I am thinking of instaling another filter before fuel flow sensor, but would like to know whether serial is ok.

Regards,

[cjkrit]

Check out the following site: http://www.challengers101.com/FuelSys.html.
Lot of detail and discussion. According to what they say both the Facet and Mikuni pump have built-in valves to prevent backflow. If so, this could make even a parallel installation quite simple.

[Duck Rogers]

Care to share your views as to why you would suggest a paralel instalation

Wargames.......cjkrit has answered the question for me
Very comprehensive article to which I have personally referred to many times.

Check out the following site:
http://www.challengers101.com/FuelSys.html.

[coen]

To all replies on the backup fuel pump. All replies and info much appreciated. Midas sparepart number on high and low pressure is the same. The only differance be-ing that the low pressure has a 42 number on the box and the high pressure has a 44 digit on the end of the number on the box . The facet pump can be blown through from both sides, so I placed it in series and it works like a charm. After having not been started for two weeks I pressurized the system and the 582 fired on the first turn

Thanks again
Coen

n

[John Boucher]

So.... you used the Facet low-pressure fuel pump?

What is the Midas part number of the pump you used please?

I suppose one would use the high pressure for fuel injected systems?

[John Boucher]

Just bought a FACET pump thought you guys may want the fitting destructions
First Specs:
on the box number is 40105 alternate number is 40242.
on the pump number is EFP-3 other side 50104 and 051805.
12volts and 1.5-4PSI.

Answered my own question.... from another thread!