Have been lurking, but have a question now. for which my searches have been unsuccessful. I have been working on refurbishing my father's 1974.5 260z. He is sticking with the flat top carbs for now. Car had been running very rich, but we just removed carbs and reset float/fuel level, which was was too high. However, earlier on we had changed the idle mixture and idle speed screw settings to try to improve the idle. I thought I had seen recommendations on starting point and procedure for adjusting idle mixture without a CO meter, which we do not have. Cannot find that method now. Does anyone know the starting point and adjustment procedure for idle mixture screw and idle speed screw?

Thanks much,

Duane.

Have you downloaded the FSM from here? Look in my signature for a link.

Also, @Captain Obvious has played with these a lot in the past.

I also think that Patton Machine might have the parts to convert these into throttle bodies. Fuel injection is SO nice. :) http://www.pattonmachine.com

SteveJ,

Thanks for the reply. Yes, have the FSM. FSM procedure for adjusting idle mixture screw requires measuring CO. We do not have access to a CO meter to do it that way.

Fuel injection does sound nice, but for now we are sticking with the flat top carbs.

Duane.

The only thing i can tell, if you don't overhaul the complete set of flattops... you WILL keep on adjusting the idle over and over until you really get sick of it!  There is no good (cheap) way to let flattops do theire job right!!!  The better advice is get yourself some roundtops!  It's the easiest fix!

Dutchzcarguy,

I hear you! I did tear the carbs down, clean everything, and did a rebuild kit on both carbs. The throttle shafts seemed fairly tight. We are just trying to get the best out of these flat tops for now. Might eventually go to fuel injection, but not at this time.

Thanks,

Duane.