Pulled the carbs off of my 240Z today to have them reworked.  There is no gasket between the spacer on the intake manifold and the intake manifold, is one supposed to be there?  More directly can the lack of a gasket there cause an air leak?  My car seems to have variable mixture making me think there is an air leak somewhere though I never tried the carburetor spray test.

Mine has gaskets on both sides. I've read of people having the wrong gaskets. They're different from early carbs without the coolant passages.

21 minutes ago, Mikes Z car said:

is one supposed to be there?  More directly can the lack of a gasket there cause an air leak?

Yes and yes.

Most noticeable at idle, and could possibly be affected by temperature.

There should be gaskets on both sides. Your can still buy them. Although I made the only set I have had and they have survived many tear downs. Seems to me the original Ztherapy video showed how to make the.


Sent from my iPhone using Classic Zcar Club mobile

Thank you siteunseen, Captain Obvious and 7tooZ, very helpful information.  I was having fairly severe idle issues.  I now see the missing gaskets on eBay.  My car needs the insulator to intake manifold gasket with no holes as there are no holes in the intake manifold surface that mates to the carbs.  I guess some intake manifolds actually put hot water through the carbs but not on my car.

9 hours ago, Mikes Z car said:

some intake manifolds actually put hot water through the carbs but not on my car.

72 does that. That's the only year that pushes coolant from intake manifold into the carbs.

Good luck and here's to hoping the fix was as easy as a couple new gaskets!

My July 71 did!


Sent from my iPhone using Classic Zcar Club mobile

The block with a gasket on each side is a little pricey, but you can also just get paper gaskets for the block you have.  They are the same as Austin Healey carbs.  Gaskets are a dollar or so apiece.  If you can't find any, try Z Therapy.  I think they're listed on their web site.

Dennis

Edited October 26, 20177 yr by psdenno

All great information.  I am sending the carbs to ZTherapy as the carbs have slightly loose throttle shafts. 

9 hours ago, 7tooZ said:

My July 71 did!

Cool. So you had the three screw round tops?  Was it titled as a 72 being built that late in the year, and you think the carbs were original?

Maybe a transition period at the end of the 71 run? Everybody talks about the mid-year changes in 74. Maybe they did that kind of stuff in other years too. 

No it was titled as a 71. My understanding is that dealers in each state titled them differently. Also I heard that in our state because there was no MSO (manufacturer’s statement of origin) from Japan the title work was loosely controlled. I have always considered it to be a Series II. No hatch vents, non solid steering wheel spikes, second gen seat belts, storage boxes instead of storage compartments. Etc...

 

 

Sent from my iPhone using Classic Zcar Club mobile

 

I thought all three screws had the coolant passage?

If your's doesn't I'd plug the thermostat housing and take off that hardline that goes behind the head. They're just possible leaks IMHO.