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MG MGB Technical - Choke cable mystery

Has anyone ever wondered how the choke cable actually works? I have HS4 carbs. The inner cable of the choke is attached to a stationary bracket on the back of the forward carb. It would seem to be impossible to pull the choke knob out when the other end is bolted to a stationary bracket. The outer jacket moves under the bonnet yet I would think this would be held stationary where it is nutted behind the dashboard.

I must be spatially challanged because I can't for the life of me figure this out!

Bob from Atlanta
RES Schultz

I thought that with HS4s that the outer was fixed and the inner did the work, although it's not unusual to have the inner fixed and have the outer 'pushing' a lever. Using this configuration, when you pull the knob, you are effectively lengthening the outer cable rather than shortening the inner cable...if that makes sense?
Dave O'Neill 2

Dave has the operation correct, the inner cable is fixed and when the know is pulled the outer sheath moves the choke lever. Cheers - Dave
David DuBois

Bob,

If the cable was laid out in a straight line then you are right - pulling the inner would get you nowhere as the end is fixed.

But in the car the cable follows a curve and when the inner is pulled it flattens the curve and shortens the distance that the cable follows so the end of the outer gets closer to the fixed point of the inner.
Chris at Octarine Services

And in the process the jet tubes are lowered away from the needles resulting in a richer mixture. Ray
RAY

And you have to check the run of the cable is free from obstructions both pushed in and when pulled out or it can be stiffer than it should be. Also check the lever on the interconnecting shaft makes a right-angle with the cable when *half* pulled. If it's too far one way or the other it can make it very stiff at the beginning or end of travel.
Paul Hunt 2

This thread was discussed between 22/07/2007 and 24/07/2007

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