I'm losing my mind over this...

[motorman7]

Probably not the best thing to do, but I did send a short blast of air into my flat tops where the fuel line goes in after it sat for 3 years. It will spray gas out the intake end of the carb. Didn't seem to cause any damage.

Make sure your choke cable is set right. Loosen the two screws that secure the choke cable at the carbs. Move the choke lever all the way forward. check that cables aren't bent or kinked and then re-tighten. This way the front and rear carbs pull evenly.

Turn that big screw on the forward carb all the way closed then back it off half of a turn.

This next item is critical! Make sure that the rubber tube that is just below the big forward carb screw and routes underneath to the rear carb is in very good condition. That means no leaks and no kinks. It is a balance tube and is very critical to smooth operation.

Might want to check your float level thru the sight glass if you have a small mirror, although it is often hard to see.

Make sure the carb needles inside your tuna cans are installed with the shoulder flush with the large piston.

You may also want to open up the idle adjust screw a couple turns just for starting and re-adjust once you are warm. That should cover most of it.

Also, I had a set of SM needles laying around so put those in my flat tops. Got those from Ztherapy for $30. They run very nicely.

Rich

Edited May 24, 2011 by motorman7

[aj92033]

Good Evening Rich, it's Anthony, we met last Monday morning where we work at. I just became a member of classic Z and was going thru the emergency post and was about to write then I came across one of your replies. I figure its probley easier just send you a message so i dont catch you at the wrong time or anything. I am trying to put a game plan together on what is ganna happen here. This weekend is probley a bad time because of Memorial day, however I will call you tomorrow and explain what my first step is going to be.

Edited May 28, 2011 by aj92033

[motorman7]

Anthony, should be here most of weekend. Feel free to give me a call.

Rich

[aj92033]

Hey Scott, I have a late 74 260Z that is having the exact same problem yours is, man its driving me up the wall. It started a few weeks ago when I came out to start my car up. It fired up and ran, then Iwent back in to clock out for the day, then no more than 5 minutes later I came back out and my car had stalled out, I spent that weekend disconnecting the fuel lines and electric fuel pump I had and testing it all. I had just put a new electric fuel pump on 2 weeks prior to this issue, I took it back to the parts store and warranty swapped it, also put another fuel filter on as well. Anyhow then i spoke to guy next door that works in this custom hot rod shop, he told me to use starting fluid. Just like what you have been doing. After spraying into the carbs X amount of times it finally fired up, but idled really rough and drove with no power. I had to drive it home about 8 miles or so. When I drove it, it felt like it had barely an throttle response. I myself hd gone through everything, I drained the tank through te bottom plug, again disconnected the fule pump and filter, disconnected the fuel lines in the engine bay that led to the fuel rail, and the lines that led to the carbs. l let the system dry out for a few days, reconnected the lines, then added a fresh 5 gallons along with the Berryman B12 chemtool, started it back up, (it still ran like crap by the way) had to keep my foot on the gas pedal to keep it running. I let it run for a half hour or so but it didnt seem to do anything. Now when I spray startingfluid into the carbs and start the car. It just burns up the fluid then dies real quick. I am right here with you in this mess buddy. And am more than willing to share any conclusions I may come to. Good Luck to us both... cheers, Anthony

[SteveJ]

aj,

Did you look at your plugs? What did they look like?

[aj92033]

well I will tell you that I had just replaced them before I had this issue, then after having the issue I fouled them due to excessive starts, so i replaced them again, and now they have fouled again, I cleaned them as best as i could but still no start. Im probley ganna pick up some non-foulers and go from there. Rich is ganna cruz by a little later and help me too possibly diagnose this issue.

[aj92033]

You should check the little filter screens for any gunk or garbage I believe they are located in the top plug on each of your carbs.

[GSCReno]

Hey Anthony... Thanks for the input and welcome aboard. Let me stir the pot here. One pair of my roundtops appears to be servicable... How much different are the flattop's manifold and linkage than the ones for the SUs??? Can I bolt 'em on and make 'em work? Anybody done this before? Share your knowledge please, Guys... Cheers, Scott

[dhoneycutt]

AFAIK the bolt pattern is the same (carb to manifold). it should just bolt Up.

[GSCReno]

Hey Dave... Thanks for your continued support, ... I might make a run at swapping them out Sunday after work. I would have thought that someone would have tried/done this before... Maybe they just haven't happened upon my desperate plea yet... Anyhoo, say hey to the family and I'll give ya a shout soon... Cheers, Scott

[motorman7]

You will also have to cap the extra waterline that runs through the flat tops. Caps at forward and aft part of motor.

[dhoneycutt]

I think the linkage will work too but...and I do mean BUT I'm only guessing on that one