The background: My 72 240z 4-speed with a transplanted 2.4 liter from a Z car with an automatic (based on distributor points replacement in a previous adventure).

The car has been running rougher and rougher and now will eventually start and idle up to 800 rpm, any attempt to rev the engine (warm or cold) and the engine bucks and air\fuel backfires out the firewall side of the front SU 3 screw carb. It appears to me that the gasket is gone but I can't find the darn part #, can someone lead me into the light or part store or give me a link to order this part? Picture attached. Thank you in advance.

Carb Insulator / Spacer search for other source.

http://www.ebay.com/itm/Datsun-240Z-Carb-Insulator-Spacer-Set-1972-NEW-/230776648727?hash=item35bb5c3417&item=230776648727&pt=Vintage_Car_Truck_Parts_Accessories&vxp=mtr

Edited May 6, 201213 yr by black gold man

Thank you Black Gold Man!

Carb Insulator / Spacer search for other source.

Datsun 240Z Carb Insulator / Spacer Set, 1972 NEW! | eBay

What makes you think the gasket is leaking? Did you check for leaks?

The throttle shaft bushings going through the center of the carb body are the notorious spot for leaks on our SU carburetors. Z-Therapy rebuild is the cure...

the carb insulator spacer is available from Nissan.

Measure the one you have, there are at least 2 different thicknesses of carb insulators.

Bonzi Lon

The thinner one is for a 260Z and the thicker one is for a 240Z.

Dave Ruiz

The thinner one is for a 260Z and the thicker one is for a 240Z.

Actually, you can't say 240 or 260. Don't forget... They put flat tops on 73 240's. Hehe.

So I believe the more accurate answer is that the thinner one is for the flat tops (73 and 74), and the thicker one is for the round tops (anything up to and including 72).

Yes, the 73 had the thinner ones. If you try to use the wrong ones the linkages will not hook up properly.

Bonzi Lon