Mark Maras

There were many different ways of dealing with them. Most were left intact and plugged. On my 260 a PO had cut the tubes shorter, and left them in place and plugged. On yet another, the tubes had been pinched closed and plugged. Other's were just removed. Were the plugs in the manifold difficult to remove? Most of the time they're a PITA. Addressing the other problems. A vacuum leak will make an engine run lean normally causing a higher idle unless the mixture is already too lean. Looking at your plugs at 2.75 turns a v. leak could be a possibility. Could also be the floats are too low. But it seems to me that there are two (or more) separate problems going on here. One is the plugs loading up at idle. The second is the engine running lean at everything but idle. Just trying to clarify what's going on.

That confirms it. I'm assuming the next gen. flat top started in July

I'd dump them. IMO, the only reason to keep the tubes is originality, if that's a consideration.

Free play at the top of the pedal stroke can SEEM to be free play at the throw-out bearing but it can also be wear in the clevis and pin at the top of the pedal. Leaving the bearing engaged at all times. Do you have an adjustable clutch rod?

Cliff, do you have a little free play in the clutch release arm when the clutch is out? The clutch that went into the RX7 was an Excedy. No throw-out bearing noise. basically the same set-up as a Z.

That looks familiar. My son and I installed a new clutch in his 81 RX7. Interesting time removing the pilot bearing. Puller wouldn't grip the bearing. Ended up using bread, a socket and extension. I'll never buy another pilot bearing puller again.

I've never experienced shimming an old style round mount starter. Just the newer flat mount ones that Chevy uses. I agree with Cliff. Pull the starter inspect the flywheel teeth, check the starter and be sure that the starter solenoid is getting full voltage.

The starter grinding can be worn teeth on the starter or flywheel. Most common is a weak solenoid often caused by a voltage drop to it. You shouldn't have to turn the engine much (just a couple of degrees) to align the starter teeth with the flywheel. Throttle problem could be lack of return spring(s) (gas pedal and engine), or lack of lube. What did you mean when you said "it" wouldn't turn off? Starter? Engine?

The conversion to the earlier round tops from flat tops was probably the most popular throughout the years. Now days, it's quite rare to see a late 72 - 74 with the original flat tops.

Any change in the engine performance when it was tapping?

I agree, IF the drum brakes are well maintained.

I think I see some poor, lumpy bodywork in the right quarter panel. The raised body line that runs the length of the car disappears at the wheel well and appears again towards the rear. The left q. panel appears to be more original. The hatch seems to fit well. Same for the right door. The left door fitment is off. The uncracked dash is rare. Probably means that it was covered well over the years. Looks to be a good buy, IMO. I'd take it back to the orig. color.

A vacuum leak would add more air to the mixture. The normal symptom of a vacuum leak is a higher RPM at idle. Remember, anytime you suspect a lean condition, you can ease the choke on and see if performance improves.

Still looks too lean. The white porcelain should be a tan color. Does it still run rich at idle and load up (turn them black) the plugs? I'm assuming the pictured plug had little idling time. Please confirm.

@jalexquijano Sitting here thinking back to what I believe was the original problem, which was the plugs loading up and getting sooty at idle, I visited the "WayBack Machine" and remembered something from long ago that I ran into. Another possibility that would cause that condition is a barely leaking needle(s) and seats and or excessive fuel pressure. Theoretically, a less than perfect (but not belching fuel terrible) seal can allow excess fuel to bypass the needle and seat and raise the float level at idle when the engine is using the least fuel, causing a rich mixture. The longer it idles the higher the fuel rises in the float chamber. As the engine rpm's and load increase the excess fuel in the float chamber is used and the fuel level returns to normal. Did you ever notice plugs 1, 2, and 3 being lighter or darker than 4, 5 or 6? A possible sign of one carb leaking. Kind of a shot in the dark but your symptoms seem to relate to this. It 's not that uncommon in carbs. Thoughts?

According to ZTherapy's Spotters Guide, the flat tops started in June 1972 and lasted through the 260. 1974.

Check out Craig's List, Portland Or. There's a couple of Z's that may be what you're looking for.

In the overhead pic of the engine, note the discoloration around the battery compared to the opposite side by the brake master cylinder. Discoloration doesn't look too bad until you pull the battery and find the fender well, firewall and the frame are all severely compromised by rust. If they are still there, that is. Z's have some areas that are prone to rust. When looking for a Z, find the best "rust free" chassis that you can afford. Period. Mechanical bits on the Z's are well built and easy to repair. Can't say the same for the bodies.

You don't avoid it, it's part of the tuning process. I would suggest that while you're idling in traffic, keep the RPM's up at a happy idle, maybe around 1500 RPM's or a little more. Or, if the engine starts easily when warm, shut it off when you have to sit and idle. See if that will keep the plugs from fouling. The needles, springs, float level, could cause the sooty plugs at idle. I think you had SM needles, what color springs are you running? I know you set the floats but you wouldn't be the first person to have to go back in and tweak them a bit. I won't be convinced that they're right until you pull the domes and pistons and tell me what the fuel height in the jet is at 2 1/2 turns down.

No

@Redwing

Go to 2.75 and check the plugs again after a few days. Small incremental changes. Try to keep the drive the same between plug checks. In other words, if the plug readings have been with, say, 1/4 traffic and 3/4 highway miles, try to keep the percentages the same. Don't read the plugs after idling in traffic one time and after highway miles the next. Try heavier wt. oil in the carbs and see if it helps throttle response. Heavier oil shouldn't affect the idle.

Yeah, too lean. The color should be light to medium tan, not white.

Many members have reported using 1993 - 2002 Kia Sportage weather strip. Some of the Z weather strip is a bit too hard or over sized and prevents the door from closing easily. Occasionally requiring a door adjustment.

Some years ago I read about owners of Oregon vehicles with branded titles, registering them in Washington and then back to Oregon. Seems in the transition back to Oregon, the "brand" on the title would get dropped. The car then had a clean title.