I have a 73 240z in which I am trying to swap out the flattops w/ a set of 72 SU's. The weather is a bit cold, so I am dragging my feet since I don't plan to drive the Z in the snow! I have zero experience w/ carbs, but these seem to be fairly simple. I did a basic tear down of the 72 carbs and found a few things.... The tubes in which the needles reside were stuck firmly and would not move freely like they should. I was able to remove them, but ended up pulling one of the nozzle ends off during this process. I guess this needs to be replaced as this is the seat, right? I also removed the float lids and it appears that one of the floats is bent severly and is either melted or damaged under the float arm. Again, I guess this needs to be replaced. I believe these carbs will be fine w/ a new set of nozzles and a new float, but wanted your opinions on whether or not you felt I should replace the needles as well. They look fine, but how can I tell whether or not they need replacing?

Also, what does everyone recommend regarding air cleaners? I don't believe my 73 air cleaner will fit the 72 carbs, right? What other options besides K&N? Also, where can I get the hardware to mount the air cleaners, etc?

Sorry for all the questions, but this is just the start... Once I get to the actual swap, I will have a whole other list.

Tx,

Bill

I have a 73 240z in which I am trying to swap out the flattops w/ a set of 72 SU's.

Also, what does everyone recommend regarding air cleaners? I don't believe my 73 air cleaner will fit the 72 carbs, right? What other options besides K&N? Also, where can I get the hardware to mount the air cleaners, etc?

Sorry for all the questions, but this is just the start... Once I get to the actual swap, I will have a whole other list.

Tx,

Bill

Here's a thread with the Ztherapy link www.ztherapy.com and some misc. info.

http://www.classiczcars.com/forums/showthread.php?t=18409&highlight=ztherapy

Forgot to mention, I think ZTherapy has an adapter to put the 260Z air box on the round tops or you could search eBay for a used 240Z air box.

First of all, I'm here in Denver freezing my a$$ off. Second, Go240Zags is right. Check out the Ztherapy site. They have a rebuild kit that includes nozzles, needles, jets and seals. they should also be able to provide the floats for you. However, you may want to consider using your carbs as a core and buying a set of rebuilt carbs from them and be done with it. One of the major problems with the stock SUs is that the throttle shaft bushings and shaft get worn and create a vacuum leak that can adversely affect performance and tuning. Unfortunately you can't effectively test this without the carbs mounted and the car running.

Ztherapy can also sell you an air cleaner or an adapter to make yours fit. To save money, check eBay or your local junk yards. As a last resort, I know a junk yard that has one but it is buried under several engines and tough to get at or I would have grabbed it already. If you get desperate let me know and I'll see if I can help.

Also, what does everyone recommend regarding air cleaners? I don't believe my 73 air cleaner will fit the 72 carbs, right? What other options besides K&N? Also, where can I get the hardware to mount the air cleaners, etc?

Sorry for all the questions, but this is just the start... Once I get to the actual swap, I will have a whole other list.

Tx,

Bill

If you want an earlier air cleaner, I have an extra that I'll let you have for $10 (that includes shipping). It doesn't look great, but it will work.

Steve

I talked to Bruce and Pam from Ztherapy and I have an old SU video tape that has explained quite a bit. I think I will try and fix what I have before spending $600 for a new set(althought they look pretty nice). I took a quick look at the throttle shafts and they don't look bad, but I understand the need to see them operate in order to see if there is an issue. They have to be better than the non-working flattops that I have on it right now. I just need to get the new parts and put them on the car, but like Enigma said, it is like 10 below right now and the garage is not the place to be. I have read a bit about the intake manifold as well, but not sure I need or want to swap it out.

Steve, I will send you a PM.

Bill