Zenith 175CD 5T carburettor

[John L]

I understand that this carb could have been fitted to USA TR's and Spitfire cars with the emission stuff on.

I'm looking for some info on 3 items that I don't seem to be able to find anywhere.

I'm playing with an auto choke model, and would like to know how to set the butterfly idle screw, its fitted with a 10mm spanner sized locknut. So I would think its set once and never needs setting again?   I cannot find any reference to the base setting for this screw, I'm beginning to think that it should be set with the butterfly just about to open, and that the idle speed is then controlled by the idle bypass valve, am I correct?

The other item I'm after is the depth of how far the fixed main jet is pressed in below the bridge, from some info I think it should be 0.100" below the bridge is that correct, and not in the middle of the jet as that is a bit recessed?

The last item is that there was a Delrin washer on the adjustable fuel metering needle, that is attached to the dashpot but that seems to have disappeared, is this part of the needle part number, again I cant find any info even on the Burlen site.

Any info would be greatly appreciated, I do have a Haynes book on Zenith CD carbs but it only goes up till 1976, and I think the carb I have is much later 1979/80 so no info.

John

[peter clarke]

Become an instant expert by looking up on U Tube. 

[John L]

But it doesn't,  that's why I asked here! 

John

[harlequin]

John

This may be of help  https://www.buckeyetriumphs.org/carburetors 

Hopefully Poolboy will see your post and reply, he will be able to give you an answer 

George