Petrol Tap

[Alan Stanley]

I have recently pulled apart a tap (normal/reserve) that is in the earlier Jupiter fuel lines and located behing the driver. The circular cork gasket, presumably 60 years old was distorted and torn. This was not the tap from my Jupiter but I feel my tap may be the source of an air leak into the fuel system indicated by constant ticking of the fuel pump.

What I am interetsed in is:

1. Has anyone sucessfully overhauled this tap with a new gasket material?

2. Has anyone just done away with this tap? What did you do?

3. Looking at the tap from the front of the car which way is normal running and which way is reserve?

[Forumadmin]

The tap is not necessary especially if you carry a can or look at the fuel gauge regularly. It can also be a problem if you forget which way around it is!
We did think on rallys of having a spare tank as some legs did not have an open petrol station late at night. If you are using your Jup for long journeys, then good on you!

[Andrew Henshall]

To answer your question re the orientation of the petrol tap for the main & reserve tanks, I referred to the early Jupiter Instruction Book. Page 35 Figure 20 shows the petrol tap, but neglects to label which is main & which is reserve (auxiliary). As my early Mk1 Jupiter is completely dissassembled at present, I then thought I could simply look at the tank & lines, but unfortunately, I can't remember which outlet from the tank is the main & which is the reserve! Sorry.

As far as replacing the cork seal, I would recommend making a seal from Nitrile rubber (also known as Acrylonitrile-Butadiene (NBR) or Buna N) as it is resistant to petrol.

Cheers,

Andrew Henshall
E1SA 433R

[Space54]

Alan,

Further to Andrew's post-I have the facillities to mould a sheet of nitrile rubber compound 6" x 6" X 2mm thick. If you could cut your new gasket from that then please PM me your address and I'll send you the rubber sheet.

Keith

[Alan Stanley]

Thanks for the offer Keith and I may take that up, but I guess I am considering the easy option of short circuiting the tap and making this one less thing to go wrong as long as I watch the fuel gauge which you rely on on for most cars. I understand that this tap was discontinued on later Jupiters (enough said)

Yes this tap is shown in the Jupiter "Instruction book" but as mentioned in a reply above does not indicate which position is reserve and which is normal , hence my dilema when by passing the tap.

I have asked around a number of Juipter owners and am amazed that no one knows which position is which an, indication that no one uses this.

So there is air getting in the line so, I need to take action befor the 1500km journey to and from the NZ National rally. So if you know the which is the reserve fitting let me know SOON.

Cheers
Alan

[Leo Bolter]

A simple way to determine which is which, is to have some fuel in the tank and (provided the two pipes are accessible at the change over valve . . . and able to be disconnected) to set a syphon going into a container on both supply lines at the same time. . . . The first that stops running is the normal supply and of course the one that runs longest is the reserve. Naturally that's the one you would use when doing away with the valve and/or the reserve function.
Or:
Maybe attach a couple of short lengths of plastic tube to the two pipes and blow into them one at a time while having a assistant listen at the tank filler for the difference in the sound of the bubbles rising through the fuel. There may be need for a "calibration" of the sounds made by having a short and a long tube inserted into some water in a 2 litre milk bottle or similar. I would think that there'd be a marked change in "tone" from one to the other . . . note the high and the low sounds and which pipe they belong to.
There are other methods I can think of using "U" tube pressure readings . . . but lets not go down that track . . . The first suggestion is the easiest and most convienient.
Leo