Carburettor needles

[NATONEIL]

My Suffolk is fitted with a 4.2 XK engine breathing through 1 3/4 inch HS6 Carbs. It runs well but is a little rich at the bottom end.

If anyone else on the board uses either 1 3/4inch HS6 or HIF 44 carbs on a 4.2, I would be grateful if you could let me know what needles you are running and tell me how your car is performing.

Thanks

[4jagsjohn]

Neil my SS has the same carbs as yours on a 4.2 from a 420. I have been on the road for 4 years plus and the car runs well but like yours it always smells a bit rich at tickover and at lights with a following wind it does sometimes smell a bit fumy. In answer to your question I dont no which jets are correct for our set up. If you read up on this subject its pretty complex. I rebiult my engine entirely and fully overhauled the carbs using an overhaul kit from Burlen fuel systems complete with new jet heads and needles.As my car runs well I have been loath to alter the mixture any further so am living with it putting it down to the joys of classic car smells etc!!.Sorry Niel not really any much help to you but at least your not alone cheers John. N. B. My carbs are 2 inch.

[NATONEIL]

Thanks John. I have swapped my carbs for the 1 3/4 inch HS6 but can not get the mixture right.
My fuel economy has improved and the car drives well but I would like to lean out the bottom end and thought I would ask what other drivers are using with 13/4 inch carbs and then look at the books with their needles as a starting point. I was told the best needles for the 2inch carb are BBA.