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Are you turning the carbs upside down to adjust the floats? That is on the SU video from ztherapy but it doesn't work with the valves you buy nowadays. They were using Grose valves in that video. Those are built different and would not hold the weight of the floats while setting the gap between the float and the lid of the float chamber. The newer needle valves will not hold the floats up. I fought with this for a long time then made my own "float chamber" out of a clear glass jar and set them that way. That's been about 10 years ago and I haven't had to touch them since. They run great. I got rid of the lid with long ears and use two short ear lids essentially turning them from 3 screw carbs '71-'72 to early four screw carbs '70-'71.

I had a knee replacement last November and didn't touch either one of mine until a week ago. I had to tap my carbs with a hammer to unstick the floats after hooking it up to a gas jug with new 93 octane and let it run straight from the jug to the fuel pump. It spit and sputtered, smelt like she-it but only for a few minutes. I followed Phillips recommendations on removing the tank, so read over the first of his "tips and tricks" to drain that fuel out. https://atlanticz.ca/zclub/techtips/fuel/gastank/index.htm

CO, I see the last message in this thread is from Sept 2024. I've spent many,many hours trying to get the float set properly, I've had the same problems all others have had. I've bent the tabs many times and have hit their limits. I'm convinced that adding ballast weight to the floats seems like the best idea. I like the idea of using a brass screw, either off the shelf or fabricated. I have a lathe, so I can fabricate the screws. What did the screws end up weighing? I am pulling the flat top carbs and replacing them with 240z carbs. The ears are one long and one short, so appears they came from a 71-72Z. I hope to hear from others - Jim Sacramento, CA. emptech@surewest.net

so far its running and ive been doing just that. thoughts on what clogged the fuel pump even though there was an in-line fuel filter between the tank and pump?

I just rebuilt the carbs and started with them both 2 full turns down, but after the above difficulties moved them both to 1.5 turns based on the service manual.

Still in original packaging. $10.

Modern fuel goes bad quickly, by design... You could: Drain it Dilute it or get it running and run it out, then add fresh

The nozzles are normally set 2 1/2 turns down from the top. Have you checked to see what yours are set at? They may not be the same.

I just got my '71 240Z back on the road last week after it sat for too long - longer than your car did. It wouldn't start for me so I had it trailered to a mechanic. He put in a new battery (Old one wouldn't hold charge, replaced under warranty), cleaned the carbs, drained the tank, and put in five gallons of fresh gas. When I picked it up it was a little hard starting and rough running until warmed up. His advice was to run it every day. After three days it starts easily and runs smoothly. It has a 20 year old electric fuel pump that continues to pump well. I'm guessing your pump is OK. But I'd drain the tank and work with fresh gas.

Phot says it all. Sand, paint and ready-to-go $25

My l24 with SU carbs is up and running but I’m having trouble with the air fuel adjustment. I adjusted timing to 5 BDTC and balanced the carbs using a synchrometer. Idle is around 750 rpm. When I use the piston lifter on the front carb rpms increase and then come back down but the engine will then die if I don’t let the piston drop. When I use the piston lifter on the rear carb rpms increase, stay increased (around 1300rpm) and the car backfires. When using the piston lifters ideally rpms will increase and then drop back down without the car dying correct? It seems like the front carb is a bit lean and the rear carb is rich but they are supposed to be adjusted together correct?

The gas in my tank is probably ~6 months old at this point and the car had been sitting for around 2 months (without fuel stabilizer in the tank) while I am redoing its interior. I was traveling a lot for work and when I returned and tried to start the car, the battery was dead. After charging it, I found that the car wasn't starting and traced it to the fuel pump. After a lot of poking and prodding with the test light I found that the wires to and from the pump were getting pretty hot so I gave the pump a few smacks with a hammer, as some orange gas was starting to sneak its way out around the hose (not a great color for gas), and it started right up and I let it idle for ~20 minutes while I added fuel stabilizer. Question - the car ran great, do I need to dump the tank? Should I replace the fuel pump if it's working now (its only about a year old)? did the pump somehow rust shut internally (the tank is around 3/4 full with 93 octane fuel which probably has ethanol in it).

The color more than anything but it does give you another leg to stand on.

Does that help your back or make it worse?

I just this morning realized my '72 has all Nissan glass except the front, PPG. That means it's not 100% but a busted windshield on a 53 year old car isn't a deal breaker. It does have the blue-ish tint sun visor.

Glad to hear you made it home and the radiator didn't become a bigger problem. Glad we got to connect last week! Planning to get the cooling sorted so you can drive it to Pheonix next year? It's only like 2,500 miles haha.

Glad you came to ZCON and gave me some inspiration on my future engine! I got a pic of our cars together and one of yours at the show Saturday. Hope to see you again at a future event!

@Captain Obvious Curious, once your back gets rested what are your plans for the car now that it has pretty much proven itself as road worthy?

Hi Bruce! I am glad you made it home ok. Relax, maybe get some back massage?

I present to you, road weary from about 2000 miles of adventure... The OG:

So I'm home. The bottom line is that the car fared better than I did. Remember in the beginning, I was worried about two things... My radiator and my back? Well the radiator didn't get any worse, but my back did. By halfway through the day at the people's choice show, I was hurting. I'll survive, but it's unpleasant. The radiator... I had talked to a couple people about the troubles I was having and they put it out on the Z network that I was looking for a radiator to get me home. Well as a result of that networking, there was a guy coming to the people's choice show that was going to bring me a radiator. We found eachother at the show, and I snagged a rad. He wasn't sure of the condition, but was optimistic about it. Said it looked good, and as far as he knew, it was in good shape. That night, @madkaw and I swapped radiators after the banquet. Out in the parking lot, draining the fluid, pulling mine out and tossing in the replacement. Now remember that my back is pretty much shot at this point, so when I say "we changed the radiator", I really mean "he changed the radiator". So when he wasn't looking, I snapped a pic of madkaw working on my car: Bottom line? We had to do the job twice, cause the replacement rad I got from the guy at the show leaked horribly and wouldn't hold coolant. Sigh. So, we drained again and put my original back in. It holds coolant fine, but has a couple clogged tubes. I'll just have to watch the temps on the way home and adjust my speeds and load accordingly. My original radiator works fine until I'm going up a long hill on the interstate at 70 on a hot day. Thankfully as I drove north, the ambient temps dropped some and I was much better off. By the time I got to Maryland, the temps had dropped enough that I was able to maintain 70-75 on the interstates without worry. Thanks to everyone along the way that helped with the trip and glad for the chance to meet some of the forum guys!! @madkaw @Ninjaneer11 @zed2 @Parman @inline6

Did you get home ok?

Great meeting in person too. And agreed.. Wish we had figured it out sooner and spent more time together. See what happens when you stop hanging out here? ☺️ I've got a pic of you working on my car. I'll put it in my adventure thread. Haha!!

Phoenix I think it will be in September...not like I have to work that week... :)