i have a question i hope can be answered today

i have a stromberg on a 2.25 engine. the carby is in reasonable condition as is the engine. recently the accelerator pump failed and i put a carby kit through it and everything was fine. However, it has always run quite rich, it used too much fuel and as soon as i looked at the choke it flooded/fouled. I put an adjustable main jet in last night hoping to fix this problem.

when i wind the needle all the way in, the car still runs all through its rev range, and is still too rich (but is slightly leaner)?? with the needle out 1-2 or even 3 winds it doesn't seem to have any effect. in both cases there is no real difference to the performance of the vehicle and it doesn't belch black smoke???

Any ideas

Cheers

Ben