Identifying which carbs are fitted

[Geoff-R]

Hi all, I've tried to identify these by looking at them but I'm wondering which exact model they were removed from. When I got my 1974 260Z from the states they were already fitted with a spare pair on the boot. I can only assume that the previous owner removed the flat tops as they were either out of tune or too restrictive due to emission laws.

Can anyone help me identify which model and year these carbs are?

Thanks in advance

 

[Rob Gaskin]

Those are the Hitachi carbs fitted to 240Zs, a common 'upgrade'.

 

[Geoff-R]

Cheers Rob, as suspected. Were there any variations over the years other than the usual 3 or 4 screw dome setups? Did the number of screws on the dome denote a certain year?

 

[uk66fastback]

They will have some numbers on somewhere ...

 

[SeanDezart]

http://www.ztherapy.com/

Spotters guide : Z

 

[Geoff-R]

Thanks Sean, looking at that then it looks like it's the 'no tab' version from what I can see.

 

[uk66fastback]

Plenty of info online as to how to set these up. How are the chokes working Geoff? If they catch or bind then it puts pressure on the lever on the console - and that's a weak point as many break off (they are attached to the underside of the console) ...

Are they operating smoothly, both extending down when operated(and evenly)

 

[Geoff-R]

The choke cable is a bit stiff now that you mention it, at present the console is removed so I've been operating the choke by pulling the cables and holding the metal bracket in the other hand. I'd assume this is the reason why every console I see is cracked right where the choke lever would be?

 

[toopy]

The choke cable is a bit stiff now that you mention it, at present the console is removed so I've been operating the choke by pulling the cables and holding the metal bracket in the other hand. I'd assume this is the reason why every console I see is cracked right where the choke lever would be?

With the choke cables disconnected at the carbs, tie/prop them up as vertical as possible and slowly drip some light oil down the cable's.
Loosened mine up a treat a few years back, and they are still nice and smooth

 

[uk66fastback]

Geoff, you think right. Well known weak area, especially with brittle consoles 40+ years old.

Toopy has it right, if you can at least get some oil into the cables it's good. You can buy a little fabbed part from ebay and elsewhere in the US - that you bolt to the tunnel of the car and that takes the force of the cable being operated (not the console) - pricey at $45 plus shipping! If someone over here had the chance to put one together for a reasonable fee they'd get a few orders I am sure.

if you look at the choke operation under the carb, you'll see there are all manner of arms moving, being slightl bent etc, it only takes one of these to have to be forced through crud accumulating over the years to put enough force on some part of the choke mechanism in the cabin to break it. Ask me how I know.

I'd remove those carbs and probably just get them working as well as you can for now, setting the jets correctly etc and plan a rebuild later - if they are basically okay - no vacuum leaks etc.

 

[Geoff-R]

Top tip with regards to the cables being oiled up, I'll do that as they are a little stiff and could benefit from operating a little smoother.

They appear to be running okay for the moment so will probably do as you say, get them rebuilt later on. Would you be able to point me in the direct of the best source of info with regards to setting these up? I'll be honest, growing up in an age where fuel injection has been the mainstream I've got limited knowledge of carbs and their setups but I'm sure they're not complicated when armed with the correct knowledge.