Petrol everywhere

[burnham28]

Have just started the car and heard the petrol pump clicking away got out of the car and there was petrol running out of the carburettor. Took the top off the float chamber and noticed that the plastic float was full of petrol. Should there be any in there and could this be the cause of the flooding and the pump continuing clicking.

[mogbob]

Hi
Your diagnosis is spot on. The float has sprung a leak, sunk to the bottom of the fuel bowl. The needle is "open " and petrol flows in. It overflows through the small hole , behind a small metal cover plate underneath the inlet pipe from the fuel pump.
A replacement is needed , plus a float chamber gasket.
Assuming you have a standard SU carb HS2 then what you need is :-

http://www.morrisminorspares.com/search/all-products ESM do a kit of the plastic float and gasket WZX1300 Part No CRB227 £10.74 inc Vat + postage £2.29.
Another source http://www.sucarb.co.uk( Burlen Fuel ) do a similar kit WZX1300 £11.16 inc Vat + postage £3.95.
Being the specialist company , they also do two other kits 1. WZX1304 with a superior "stay up " float i.e it won't sink like a plastic one does.
£16.44 inc Vat + postage £3.95.
The hole hog would be their WZX1304A kit , Stay up Float , gasket, and new needle valve £21.95 inc Vat + postage £3.95
SAFETY
Don't forget to disconnect the battery ,work outside or with plenty of ventilation and no source of ignition near by. Don't work on a hot engine , rags underneath the carb and fire extinguisher to hand.
P.S just another thought is the rubber pipe... Fuel pump to carburettor ... still in serviceable condition , rubber not perished ? If it is then replace now , whilst you're working on the carb.
Good luck
Bob

[burnham28]

Thank you for your help and advice. Thought the float shouldn't have any liquid in it so have taken your advice and ordered the Whole hog service kit from the Sucarb Co. apparently these floats do not leak as they are made to military specification.

[mogbob]

Yep.. they are supposed to be a " fit and forget " item those floats , I've heard a number of good reports.
Bob

[burnham28]

Have now fitted the new float and everything seems of be working correctly. The kit came with a new needle valve and seating but how do you get the seating out of the body, it is screwed into the float body but it is so tight to the sides that I can't get a spanner to fit, it seems to need a very thin box type spanner to fit but I have never seen one that thin. I have left the old needle and valve in place which seems to be fine at the moment.

[mogbob]

Getting a needle valve out of an SU carb float is very akin to brain surgery I guess.
I use a long reach socket A/F 11/32nds on a 1/4" drive ratchet because it's thin enough to get down over the brass body. A metric 9mm , whilst not a perfect fit , will get you out of a spot of bother.

As you've already discovered it's all about the thickness of the socket / box spanner wall. You might find , if you have one , that what I call a " cheapo " mini tool kit for the office desk ...has a small enough 9mm socket to at least get a reasonable purchase / hold on the
end of the brass valve. Worth a go. If you are still struggling , a little trick is to put the whole float lid in boiling water for a minute or two
to expand the metal / break the varnished dead petrol seal. Take it out with some pliers , hold with a pair of rigger type gloves and with socket to hand extract !
Once out a blast of carburettor cleaner in the valve seat area , left on for a minute or two , will ensure the new valve goes in easy when the lid has dried out.
It's worth having a go.
Bob

[burnham28]

Found this in an antique shop couldn't resist it at a fiver. Its about 12 inches by eight. Probably quite commom but I've never seen one before.

[philthehill]

For removal of the float chamber needle seat you need one of these.

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

Whilst removal of the needle seating can be done in other ways - having the right tools makes the job so much easier.
I have had my needle seat spanner for many years and it still comes in handy even now.

[edd_barker]

Mogbob, you deserve some sort of reward for your original reply, the OP could not ask for more clear, concise information if he/she tried! I salute you.

The forum reaches new heights of helpfulness!

Edd

[David W.]

These are very handy. They also make it less likely that you'll over-tighten the valve seat.
http://www.ebay.com/itm/Craftsman-7-pc- ... Swr~lYqlWb

[philthehill]

David.W
I doubt that the drivers in the attached link will do the job for the following reasons:

The needle seating is deeper than the apparent internal depth of the spanners shown.

The recessed space around the needle is very tight and the SU needle box spanner has a reduced diameter of 12mm external diameter x 18mm long where it fits over the needle seating and then will only just fit into that recessed space.

As regards over tightening - the 'T' bar of the spanner at 54.5mm long overall is designed to limit the amount of torque applied to the needle seating.

If you repair/modify SU carbs you do need to have one of the dedicated needle seat spanners or a dedicated box spanner turned to the above dimensions.
Phil