I think I'm missing the carburetor fast idle set screw

[Jeff Berk]

Hi all,

I have a '74 260z with a 280 engine/5-sp manual that I purchased a few months ago. In the early 80's, a triple carb system was installed in it. Then around 2010, it was changed back to a dual SU carb system. I was trying to adjust the carburetors and could not locate the fast idle screw.  After some digging on the internet, I think it's missing (see second picture), maybe during the switch back to dual carbs and the addition of the nifty bolt as a vacuum plug. Is this something I can easily fabricate out of a triangle of thick sheet metal with three holes, a screw for adjusting and maybe a spring around the screw? If not, anyone can suggest a source for this missing part?

Also while I'm at it... The first picture is of the bottom of one of the carbs. Is the knurled nut just below the carb the air/fuel ratio adjuster? 

Thanks!

Jeff

Edited July 28, 2017 by Jeff Berk
pictures were switched

[JSM]

Yes it is missing. Yes that is the adjustment for the Fuel mixture. 

Post a WTB thread in in the parts wanted. If that doesn't pan out you may get lucky and Ztherapy has one. I was missing a single choke cable collar and they had it. 

What air filter and velocity stacks are those?

Edited July 28, 2017 by JSM

[Jeff Berk]

JSM... Thanks for the info. I have no idea where the velocity stacks originated from. I had to wrap the ends of them with self-vulcanizing electrical tape to build up their diameters so that I could install an air cleaner. The Air cleaner/filters were just inexpensive universal units I purchased from Autozone. I know it was jerry-rigged but less so than that of the PO.

[Fred Sigarto]

Glad you got on this Website Jeff, these guys are great, they can help & give you the best info on any problem you have.