[Laird Scooby]

If memory serves you'll need a long 3mm Allen key for the misture screw. A quick test of the thermotime switch would be to unplug the electrical connector from the cold start injector once the engine is running, if it smells less rich and the idle smoothes out then suspect the thermotime switch.

Something in the back of my mind says the thermotime switch is on the back end of the left hand side of the head, under the inlet manifold. Might be wrong though.