eratic idle / Zenith carb Idle solenoid

ive got a constant problem with my idle speed being eratic, every time i got off roading and shake my old series 3 about the idle slows down or speeds up and its really anoying as it will sometimes cut out. so far ive put a lock nut in the idle speed screw, replaced my: coil, points, condenser and set the dwell angle and ignition timing, checked ht leads, cleaned and checked/gapped the plugs.

theres only two other possibilities i can think of, the carb or head gasket. ive clean my weber numerous times to no avail so im going to try the old zenith but im stuck, where does the wire on the side of the carb go? im guessing its a solenid for the idle or as an anti run on valve but how do you wire it up? does it go to the positive on the coil?

any other ideas about the eratic idle?

cheers Tim.

if its only when yer orf road, then one could take the view that it is bump related. are yer injun mounts ok? if them is fooked then, with the rod accelerator linkage , any shift in carb/engine will move the throttle on the carb

it happens most after big bangs or after a prolonged periods of wide open throttle followed by shutting off, then it starts to surge.

any idead about the wire on my carb? were do i put it?

give us a piccy - it could be either of two shut-off valves.

ill get a pic tomorrow, there is only one solenoid, its on the oposite side of the carb to the throttle linkage and is angled back towards the bulkhead. its screws into the carb and looks like a needle on the end (the end in the carb).

fuel cut-off solenoid. i believe it is connected to the lt input side of the coil.

this is the one, i cant see where the wire goes though, blood air pipe!