Switching to SU's today

[xxjoeyxxeb]

Hey guys,

Today is dedicated to rebuilding a set of 3 screw SUs to put on my 74 260z! I am starting in 30 minutes, and will be checking back here at break times, so any information you guys want to share, let me have it! Precautions, how tos... whatever. I'll keep you guys informed, and if the car runs, maybe do a writeup with some help...

[beandip]

Hey guys,

Today is dedicated to rebuilding a set of 3 screw SUs to put on my 74 260z! I am starting in 30 minutes, and will be checking back here at break times, so any information you guys want to share, let me have it! Precautions, how tos... whatever. I'll keep you guys informed, and if the car runs, maybe do a writeup with some help...

First thing , especially with 3 screw SUs , DO NOT inter change any parts from one carb to the other. Especially the vacuum piston and domes . Be careful withe the plastic locating ''pins '' that are on the top of the carb base that locate the dome to the base. Other than that they are almost the same as a 4 screw. You will need a different linkage that fits between the two carbs. Your old one will not work. Also you will need the thicker insulators that fit between the carb and the intake. If you are going to be running coolant in to the carb bases then you will need the proper insulators that will allow this , or drill out a 4 screw set . Start with screwing the fuel mixture adjustment backed out 2 1/4 turns , this should get you started and running . Then you will be able to adjust from there when the engine is warmed up . Gary

[=Enigma=]

I'll just say good luck and happy wrenchng. There's already plenty of info on these carbs and this swap here on the forum.

[xxjoeyxxeb]

Thanks guys, got them all apart and cleaned now. Going to put back together and make sure everything is equal and set up correctly.

[xxjoeyxxeb]

Anyone got help information on levelling and gapping float at .55"? ZTherapy sent me the jet that has the needle type thing, not the round ball. So when I tip it upside down the float pushed the needle down and its hard to get a precise reading... also that needs to contact that jet needle square on right?

[xxjoeyxxeb]

Got the floats all set, almost got carbs back together.

[xxjoeyxxeb]

What have people done with the line that runs from the balance tube along on top of the fuel lines to the Purge outlet on the carbon canister???

[beandip]

Man I don't know what you are referring to . There should be one line , about a 5/8'' hose that should go to the air cleaner . This is the fresh air and or blow by outlet . There are vent hoses from each carb that connects to the air cleaner as well. If you have a automatic trans , there is a vacuum line that connects to he trans , it is a 1/4'' size and a larger one that connects to the vacuum brake booster. That is it. Gary

[xxjoeyxxeb]

I took a pic of the hose. Its a 74 260z. Its the 90 degree bent hose in the middle of the screen coming up from the balance tube., it goes into the heat shield with the fuel.

[xxjoeyxxeb]

http://videos.streetfire.net/video/D287BFDB-BEC8-4DF1-9647-DAAF2075EF6C.htm