Need help with my 73 carbs . . Orange,CA

[New-to-240z]

Well, checked the oil and when i tried filling it up iut was already filled. Was wondering though, it looked REALLY red in there. I think the PO might have put ATF. What's an easy way to empty out the fluid so i can replace with 20W? I think this is what's causing my problem.

[e_racer1999]

i've always just disassembled mine.

[Mat M]

I have the round-tops, but I am using Marvel Mystery Oil in mine (also red).

Have you tried making sure ALL the throttle linkaged are properly lubed? I think they are all ball-and-socket joints that can be pulled apart. I have used teflon spray in the past, seems to do the trick.

[beandip]

The ATF in the dampeners is not your problem. It effects throttle response and can cause a stumble when coming off idle. Unless your mixture is set way rich. But not what you are describing. I have a question about the carbs. You stated in the beginning that they were the Stock flat tops isn't this correct ? Because if they are in fact round top SUs , this is another matter. I DO NOT recommend cutting any springs. Vary likely the problem is in the linkage. It is either binding or in need of lubrication. Oil all the pivot points of the linkage and make sure they are not binding . On the firewall where the linkage comes through from inside the cabin. there is a ''post'' that pivots when you activate the linkage . Check this pivot and oil it well . the white ball things on the linkage will pop off but be careful with them , over the years they tend to be brittle. Pay attention as to how the arms are when you remove the pivot. Just slide the clip off the top of the shaft and then lift the pivot off. I use white lube on this but if you don't have any just oil it good after you have cleaned it. It should pivot freely. put some oil in the ''ball'' connectors and snap them back on. If your Z has all the factory emissions stuff still attached this could also be a cause . However just do this for now. If you still are having the problem let us know . Gary:rambo:

[New-to-240z]

what do u mean by that? is do I just unbolt them from the carb and nothing will spill out?

[beandip]

what do u mean by that? is do I just unbolt them from the carb and nothing will spill out?

Concentrate on the linkage. I don't recommend that you open up the Carbs especially since you don't have a manual to compare to . The oil in the dampeners will not cause what you are describing. On Round top SUs they take only about 4cc of oil each to fill from empty. I personally use ONLY 20w and for me that works the vary best . The thinner oil causes the vacuum piston to rise quickly which causes a lean fuel/air mixture when you open the throttle. If you have the mixture set vary rich this may not be that noticeable. But you will be running rich over the rest of the RPM range. For those that run on the track it doesn't matter because they are running at open throttle most of the time . Not from idle. I have heard Z people using everything from water to brake fluid in the dampeners , I have tried ATF , Marvel Oil , and various weights of motor oil. Nissan recommended 20w . I found that it works the best for me. Second choice is 10w/30. thats my 2 cts. Gary

[e_racer1999]

true aout the linkage. when you let off the gas does your pedal come back up?

[New-to-240z]

yea the pedal comes back up but when i press down i don't feel any resistance till i hit where i left the pedal when i let go. hope that makes sense. HAHA

By the way, I have a completely stock 5/73 240z. So, i think i have the flat tops?

[e_racer1999]

are the tops of the carbs flat like this:

or round like this?

please note that the flat tops pictured above will NOT be identical to yours, and are comp carbs.

[New-to-240z]

they are the flat tops. FOR SURE. Thanx for the pic too. That helped

I was wondering how to replace the fluid in the dampner itself. I just took that black cap off and filled it up. How can i empty it out and re-fill with 20w or 3-in-1?

Also, I will be buying some white lube tomorrow and will be lubing up all the socket joints, and anything i can find that moves on the throttle.

[New-to-240z]

On the firewall where the linkage comes through from inside the cabin. there is a ''post'' that pivots when you activate the linkage . Check this pivot and oil it well . the white ball things on the linkage will pop off but be careful with them , over the years they tend to be brittle. Pay attention as to how the arms are when you remove the pivot. Just slide the clip off the top of the shaft and then lift the pivot off. I use white lube on this but if you don't have any just oil it good after you have cleaned it. It should pivot freely. put some oil in the ''ball'' connectors and snap them back on. If your Z has all the factory emissions stuff still attached this could also be a cause . However just do this for now. If you still are having the problem let us know . Gary

Now, by oil do you mean literally just regualr oil like the 10W-40 i put in the engine? Or are you talking about using that white lube? Just want to make sure, so i put the right stuff on rather then making it worse.

[New-to-240z]

i don't know if this means anything, but when i took off my intake cover and looked at the filter, i could smell gas and see that the filter was almost completely plauged with gas. It wasn't pooling any gas, but i could see white parts where gas hadn't been and darkened parts where gas HAD been!