The air intake is bi-directional; The idea being on cold the air is drawn from a warm source ( The external area of the exhaust manifold) to quickly heat the carburettor to optimally 20 degrees and so rapidly turn off the choke ( all about emission control) The flap is spring loaded bias, being controlled by vacuum bellow fed from the inlet manifold and switched via a bi- metal valve ( that can be opened and adjusted) The next problem is the overheated carburettors due to the nestled proximity between the vee blocks of the engine.. This can be offset by renewing the Bakelite spacing insulators to the inlets and; also the replacement of the steel spring washers with plumbers fibre washers.. to improve the insulation properties ( it is in no manual but does work to help hot starting)
Who carries these insulators? My auto Stag has an issue even with another set of carbs. My manual doesn't. My auto's rpm at speed is typically 3500-4000 so it generates more heat than my manual with OD with runs less than 3k.
@@sujitroy rimmer brothers for the insulating block.. part number: ERC1102A 2 off.. Get new pedestals gaskets part number 152342 four of ( each side of insulator) BTW don’t use any gasket paste as this can only lead to thermal transmission. Get some fibre washers from Screw Fix to replace the spring washers … It all helps to lower the running temperature of carb body
