09-09-2021, 09:05 PM
It is always very difficult to make adjustments when you are altering two variables at the same time. I would set the jet of the SU carburettor about 1/32" below the bridge, generally about 8 flats of the hexagonal adjusting nut. Use either an EB (Mini) or AN (Morris 1000) needle, both of these are known to suit an Austin 7.
Using a test lamp, adjust the distributor so that the points are just opening when the engine is at TDC. Fire up the engine and advance the timing by turning the distributor until the idling speed rises without the engine sounding rough.
If you can't get the engine running smoothly, I would suspect the late Ruby head. Many engines, especially if they are a bit worn, run roughly on the late head. Perhaps you could borrow an earlier head to see if it improves things?
Using a test lamp, adjust the distributor so that the points are just opening when the engine is at TDC. Fire up the engine and advance the timing by turning the distributor until the idling speed rises without the engine sounding rough.
If you can't get the engine running smoothly, I would suspect the late Ruby head. Many engines, especially if they are a bit worn, run roughly on the late head. Perhaps you could borrow an earlier head to see if it improves things?