Does anyone know which needles are used in the SU carbs on a stock 1971 240Z (L24) with orig SU's

This question could be answered by contacting Ztherapy, I am sure Bruce has the answer for you or check out their website, they adverstise on the banners atop this webpage.

At your altitude I'd be more interested in what size noozles you have. At high altitude we typically supply and undersize nozzle to make up for the rarified air.

What are the circumstances that spawn the needle question?

Does anyone know which needles are used in the SU carbs on a stock 1971 240Z (L24) with orig SU's

As I recall they were N54's

FWIW,

Carl B.

I recently bought a set of SUs that came from Colorado . They had 58 needles, I am at nearly sea level and running a ZX on carbs and after trying different combinations ended up with 54s and the engine pulls hard and runs great. As a side note , just for kicks I went through the emission testing at the state facility and passed even though I have no emission stuff on my engine. I am running just a little rich at idle but all cleans up at fast idle , 2500 rpm. I know I am running a little rich but with no cat on this '82 zx engine and all I am surprised. they were also . So you might give the leaner 58s a shot , I found them too lean for my altitude. Gary

The early 4 screws ran an N27 needle. First iteration of the 3 screws were the N54 and then they went to the N58.

At your altitude I'd be more interested in what size noozles you have. At high altitude we typically supply and undersize nozzle to make up for the rarified air.

What are the circumstances that spawn the needle question?

Bruce,

What spawned the question was the difficulty in getting the fuel mixture correct. It has always run rich since I moved to Colorado and passing the smog tests has been difficult.

I have been working with a very experienced mechanic and he discovered that the needle in the rear carb is smaller than the one in the front. I have no clue about how or why that is the case but I know that is not right.

This prompted me to post the question about what were the correct size needles.

My original thought was to get a matched set of needles and see where that got me but after thinking about your response, it makes complete sense to also replace the nozzles.

What would a set of nozzles and matched needles for my altitude (4500+ ft) cost?

Needles and nozzles are each $30 a pair......