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UK Car Repair/SU Carburettor jets


Hello Mr. Boyce
My query is regarding the jets for the SU carburettor.
I have a pair of used, good condition 1.75" SU carburettor complete with needles but without the jets.

I happen to have a few sets of old stock but unused jets for the 1.25" and 1.50" SU carburettor around. Physically they fit nicely to the 1.75" SU carburettor but I am wondering whether they are suitable for the needles of the bigger carburettor. I know the jets come in 0.090 and 0.100 sizes.

I would appreciate your views.


I suppose the jets and needles are physically the same or very similar between the carbs same as the jets, lean STD rich... , I dont see there being a problem building a carb out of all different bits either, so long as it makes a good mixture. What engine/car is this frankencarb going into? any modifications to intake/exhaust/engine?  

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Christian Boyce


Extensive knowledge of cars designed between 1900 and 2000. I have an interest in keeping these early cars on the road - I love the classics and want to keep them around. I'M BACK!. A LOT of reasonably classic cars are going TO SCRAP with no good reason. I want to stop that. If it's cool and you're having trouble with it, just ask. Also I'm looking for a job. I can do bodywork too. Not welding yet. Everything else and more though.


Too much to list............ Honest, I tried.



Elec-Installation (bolton college) Digital and analogue Electronics (Bol Col.) Digital Microprocessor Electronics (Bol Col.) - Pc Inst, Diagnosis/Repair NVQ3 Bury College.

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