Mark Maras

It acts as a sound deadener as well as a carpet pad. Necessary? No, but it will get louder in the cabin without it. A lot of owners are replacing it with Dyna_Mat or the equivalent.

Google "Jute matting 240Z", you'll find lots of options.

It depends on the outside and engine temp. I give it full choke to start it when the engine is cold. When the engine starts to run a bit rough and it starts blubbering or stuttering, I EASE the choke off UNTIL the engine sounds better. I adjust the choke to the off position as the engine warms up. If I push the choke off too soon, the engine will almost stall. You can start driving the car anytime after a minute or so to be sure the oil is circulating. Just keep the revs reasonably low. VOE speaking when I say, you can and will spin a rod bearing if you high rev one of these engines when it's cold. Be patient and let the engine warm before you start having fun. A possible help may be to adjust the choke as follows. Full choke at start. 3/4 choke when the temp gauge starts to move. 1/2 choke when the temp gauge is 1/2 way to normal operating temp. 1/4 choke when the temp gauge is 3/4 to operating temp. If the engine starts to run rough, give it a bit less choke. If the engine balks and almost stalls, give it a little more choke. Don't be afraid to experiment with choke settings while you're driving it. You won't wear out the nozzles, I promise. I can't help but wonder if a valve adjustment would even out those compression ratios. Might be something to think about when we're done with the carbs.

A scene like that is what triggers my impulsive side. I wouldn't have been able to stop myself.

@jalexquijano Sure give it a try. Be sure to report back. Inquiring minds, want to know.

@jalexquijano 12 btdc sounds about right. Do you have a timing light? If so, it would be interesting, as well as easy, to advance it a couple of degrees and see if the carb backfire goes away or gets better.

If there was no damage during the rebuild, it should be just a matter of trying all the piston-dome combinations.

Did they slide freely before the rebuild? Use a Sharpie pen on the piston. You might also try leaving the 4 screws slightly loose and gradually tighten them as the piston is being slid up and down. Did you try switching the pistons too?

@jalexquijano Actually, I'm glad to hear that you have to drive it slow until it warms up. It's a good habit to get into. Two questions. Does it backfire thru the carbs at full choke and how hard are you pushing the engine when it backfires?

@jalexquijanoNever heard of that one. Keep in mind that every time the choke is pulled and pushed it lowers and raises the nozzles just like adjusting them with the mixture screws. In my case, 20+ years of pulling the choke on and adjusting the same set of SU's never wore the nozzles out. If he was that concerned about nozzles why didn't he just lube the outside of the nozzles. My guess is, he was afraid that you'd get the mixture set correctly before he did. What other gems of information has he passed on to you. I feel the need to be entertained. How's it running?

I'm sure you meant PUSHING the choke off.

You're right, Fred was cool.

Excellent. The coughing you're describing is a too rich mixture caused by too much choke. You've figured out that the choke can and should be adjusted to suit the conditions, ambient and engine temperatures. While I'm thinking about it, should you ever want to see if the fuel mixture is too lean (when the engine is warmed up) gradually pull the choke while you're SLOWLY accelerating. If you feel the power increase the mixture needs to be a bit richer. Drive it for a few days or until a new question arises. Oh yeah, have you driven by your old mechanic's shop yet?

There are a few things that would cause dark plugs at 2 1/2 turns. Nozzle?s are sticking in the down (choke on) position. You can manually push up the nozzles with the choke off to see if they're sticking. They should be all the way up with the choke off. Choke cable?s mis-adjusted and not allowing the nozzles?s to go all the up. Readjust choke cable clamps at carbs. Float?s adjusted too high. Easy way to tell is remove the tops and pistons. With the choke off, there should be no fuel above the small hole in the nozzle that the needle fits into. The fuel level should be below the hole. I've also seen nozzles stick down because of the little flat bar linkage that attaches to the nozzle on the bottom. If both mating surface on the ends of the linkage aren't exactly parallel to the other mating surfaces, the linkage will bind. It's easy to fix with a slight twist after careful scrutiny.

Earth to Cliff. Earth to Cliff. Come in please.

@jalexquijano "choke on for 10 to 12 mins", did you leave it pulled all the way on until the engine was warmed up (presumably temp at half) or did you gradually push the choke forward as the engine warmed?

@7tooZWell said. @jalexquijano You can get a "feel" for the choke location during warm-up (while driving) by gradually easing the choke off while you're GRADUALLY accelerating. As you slowly push the choke knob forward, you'll feel the engine lose power, at that point give it a little more choke and you'll feel the power increase. Too much choke when the engine is warm will make the engine run a little rough with a decrease in power and could increase the possibility of backfire from the exhaust due to the rich fuel-air mixture. Yes, do all street tests with the air filter installed.

Tribbles are green in the Pacific Northwest.

Hmmm, I think you may be on to something there. 160` is kinda low. @jalexquijano Is it still overheating in traffic?

I just figured he wanted to keep it original, grey and wrinkly.

I don't blame Jalex for pushing it. EXCEPT WHEN THE ENGINE IS STILL COLD. One has to push "IT" (submit your own definition) every now and then to see if it's worth keeping. Who want's to baby something forever. Especially a Z or a girl.

A full tank of gas or just accelerating?

My favorite line. Captain, I'm attempting to build a pneumonic memory circuit using little more than stone knives and axes. I've felt that same way on many projects.

Cara Mia, Querida, Querida Mia, Tish, Cara Bella and Bubala, Mon Cherie, Querido

If anyone wants to know more about welding hazards, Google "Fume Fever". Been there, done that.