Petrol hose bore, pump to carb

Discuss mechanical problems here.
Forum rules
By using this site, you agree to our rules. Please see: Terms of Use
Post Reply
Edward1949
Minor Fan
Posts: 158
Joined: Fri Mar 30, 2018 1:21 pm
MMOC Member: No

Petrol hose bore, pump to carb

Post by Edward1949 »

Different sources state 5mm and 6mm internal diameter. Anyone know for sure?
KeithL
Minor Fan
Posts: 449
Joined: Mon May 24, 2010 9:06 pm
Location: Worcestershire
MMOC Member: Yes

Re: Petrol hose bore, pump to carb

Post by KeithL »

I asked SU this question when I was recently looking for an ethanol-proof replacement fuel hose and they said it was 6 mm / 0.25 inch.

philthehill
Minor Maniac
Posts: 10767
Joined: Thu Jul 19, 2012 12:05 pm
Location: Hampshire
MMOC Member: Yes

Re: Petrol hose bore, pump to carb

Post by philthehill »

The fuel pump outlet stub is 7mm O.D so a 6mm pipe will fit but of course the fuel pipes are imperial so should be 1/4" I.D...………..

As stated above must be ethanal proof.

mogbob
Minor Legend
Posts: 1280
Joined: Thu Apr 02, 2009 3:43 pm
Location: Esher
MMOC Member: No

Re: Petrol hose bore, pump to carb

Post by mogbob »

I've just got a micrometer out and measured the outlet stub on my refurbished Petrol Pump down in the shed.It measured , just the merest fraction under 6 mm.
Bob
philthehill
Minor Maniac
Posts: 10767
Joined: Thu Jul 19, 2012 12:05 pm
Location: Hampshire
MMOC Member: Yes

Re: Petrol hose bore, pump to carb

Post by philthehill »

The fuel pump (non threaded) outlet stub (Pt No: AUA1424 (MOSS)) fitted to a SU Minor fuel pump is of 7 mm O.D. (9/32")

I have physically checked the O.D. and it is indeed 7.mm (9/32").

The metal fuel pipe to the fuel pump is 1/4" O.D. (6.4mm) again physically checked against a Morris Minor fuel pipe.

Edward1949
Minor Fan
Posts: 158
Joined: Fri Mar 30, 2018 1:21 pm
MMOC Member: No

Re: Petrol hose bore, pump to carb

Post by Edward1949 »

Many thanks for the advice, have ordered 6mm and hoping for sufficient tolerance!
Supplementary fuel question : I need a new float needle valve (1968 Saloon, HS2 Carb ) and am a bit baffled by this ebay advert for an HS2 valve which excludes the Morris 1000 from the list of compatible vehicles. https://www.ebay.co.uk/itm/Genuine-SU-C ... SwvRpaq4Ne

Have they got it wrong?
philthehill
Minor Maniac
Posts: 10767
Joined: Thu Jul 19, 2012 12:05 pm
Location: Hampshire
MMOC Member: Yes

Re: Petrol hose bore, pump to carb

Post by philthehill »

The float valve in the 'e' bay link should fit but to alleviate any doubt Burlen Fuels is the place to go. They are the successors of SU and will hold all the parts required.

Attached to the carb is a numbered tag which will give the specific carb fitted to your vehicle.

AUD13 is most likely the carb fitted to your Minor and here is the link:-

http://sucarb.co.uk/carbspec/carburetto ... s/id/1907/

http://sucarb.co.uk/float-chambers-spar ... oaded.html

You will need the special spanner or similar to remove and fit the float valve.

http://sucarb.co.uk/tools-flow-meters/t ... anner.html

Edward1949
Minor Fan
Posts: 158
Joined: Fri Mar 30, 2018 1:21 pm
MMOC Member: No

Re: Petrol hose bore, pump to carb

Post by Edward1949 »

philthehill wrote: Mon Mar 18, 2019 1:57 pm You will need the special spanner or similar to remove and fit the float valve.


Is this vital, or can I improvise?
philthehill
Minor Maniac
Posts: 10767
Joined: Thu Jul 19, 2012 12:05 pm
Location: Hampshire
MMOC Member: Yes

Re: Petrol hose bore, pump to carb

Post by philthehill »

There is very little clearance between the needle seat body and the lid of the float chamber. The special box spanner has a reduced thickness lower end to allow it to fit between the needle seat body and the lid of the float chamber.
You could improvise with a correct size box spanner with the corners taken off.
If I could find my SU spanner (it seems to have gone walkabout) I could give you the dimensions but you should be able to work it out for yourself.

Phil

philthehill
Minor Maniac
Posts: 10767
Joined: Thu Jul 19, 2012 12:05 pm
Location: Hampshire
MMOC Member: Yes

Re: Petrol hose bore, pump to carb

Post by philthehill »

I have found the special SU float needle seat body box spanner and the measurements are as follows:-

Inside between flats...…………………..,,,,,,,,,,,,,,,,,,,...............………..9.3 mm (3/8").

Outside of the box spanner is reduced to...………............…………...10.1 mm diameter

The length of the reduction from the bottom of the spanner is......19 mm.

You should be able to reduce a 1/4" or 3/8" drive deep 3/8" A/F socket sufficiently to enable you to remove the float needle seat body.

There is always an up side to everything - Whilst searching for the SU Spanner I found a NOS set of cam followers I did not know I had. :D :D

Edward1949
Minor Fan
Posts: 158
Joined: Fri Mar 30, 2018 1:21 pm
MMOC Member: No

Re: Petrol hose bore, pump to carb

Post by Edward1949 »

Update : an old 11/32 socket from a cheap'n nasty 1/4 drive set fitted perfectly without any slimming down . Job done, thanks.
Post Reply