Morris Minor Owners Club

Actualy its unleaded carburettor. I think there is something in the carb which might not like unleaded fuel and need changing.
. If there is grateful if someone can tell me what! Thanks very much.
Jonathon

Leaded or unleaded fuel makes no difference at all to a carburettor.

Fuel that contains ethanol may affect certain parts of the carburettor but not necessarily. Some people have said ethanol containing fuel has caused the float in the float chamber to start leaking and need changing to a more modern float. Also certain types of float needle may deteriorate and can replaced with Viton tipped needles. Finally, there is an o-ring that seals the jet pipe where it joins the float bowl. Again this can be replaced with a Viton o-ring.

If you count the fuel pipe from fuel pump to carburettor as part of the carburettor, this should be replaced with an ethanol resistant pipe.

All of the above is only worth doing if you are encountering problems except the fuel pipe to the carburettor which should be replaced. A leak there is dangerous as it is near the hot manifold.



Stephen

Thank you Stephen. I ll replace the pipes then too easy not to, and keep a spare float in the car ,thats too easy not too too!
Jonathon

There's a special type of float now available from SU called a "stay up" float. Quite expensive but resistant to ethanol. Recognisable as it is a black colour. When replacing the o-ring on the jet pipe it is very easy to kink and destroy the nylon pipe inside the spring. There is a good video on how to do this presented by Moss Motors and I strongly advise you watch this to avoid frustration and upset. https://www.youtube.com/watch?v=ZPzu2zzyGCQ

Stephen

svenedin wrote: ↑Thu Jul 23, 2026 11:29 am There's a special type of float now available from SU called a "stay up" float. Quite expensive but resistant to ethanol. Recognisable as it is a black colour.

Yes, I think the new design is a single piece 'solid' buoyant material, rather than a plastic/polythene 2 part casing full of air.
The Ethanol probably affected the sealing of the 2 parts of the earlier one.

geoberni wrote: ↑Thu Jul 23, 2026 11:51 am

svenedin wrote: ↑Thu Jul 23, 2026 11:29 am There's a special type of float now available from SU called a "stay up" float. Quite expensive but resistant to ethanol. Recognisable as it is a black colour.

Yes, I think the new design is a single piece 'solid' buoyant material, rather than a plastic/polythene 2 part casing full of air.
The Ethanol probably affected the sealing of the 2 parts of the earlier one.

Yes it's some kind of buoyant material as you say. Solid, no seam. I have one on the car.

Stephen

A couple of years ago i overhauled the carbs on the Midget I fitted some brass olives produced by a guy in the Triumph owners club. These replace the jet seals and are E10 or even E15 proof.

https://www.facebook.com/groups/1475896 ... 531455661/

I think I paid £2 for 10 so I have fitted the same to the pickup. Never had any leaks since.

Brilliant thanks