Mark Maras

@Luis Maldonado, in post #3 you said "at 85 mph it stops accelerating and starts to fail." Describe the symptom please. Does the engine cut out? (spark plugs misfiring or not firing) Any backfire from the carbs or exhaust? Does it just run out of power exhibiting no other symptom? Any smoke, odd noises or smells when it happens?

Welcome Luis. Does your Z exhibit any other symptoms. Tell us about your set-up. Stock, with SU's? Have you changed anything lately? Have you tried any repairs?

I just heard that E.D. pills will do the same thing. Hmmm. Maybe it's not the pills.

How many beers does it take to mow 15 acres?

Too much fuel can be caused from excessive fuel pressure, floats set too high, sticking floats, stuck needle and seat or crud in it holding it open, for openers. Two other things, when the choke is in the off position, reach under the carbs and push up on the nozzles. They can stick down (more choke) even when the handle is pushed forward and be sure that the choke cables are adjusted at the carbs to be sure the nozzles are all the way up (up being resting against the mixture nut which is about 2 1/2 turns down) when the choke is off. When the suction chambers and pistons are removed, you can look down and see the top of the nozzle. Set at 2 1/2 turns down, the fuel level should be about 1/16" below the top of the nozzle.

There's been a lot of discussion about float adjustment methods. Any service manual will get you close to the right adjustment if it's done with care. As a final fuel height check, you can remove the suction chambers and pistons, with the mixture screws 2 1/2 turns down, look down at the top of the fuel nozzle. The fuel level should be about 1/16" below the top of the nozzle opening. Also be sure the floats pivot on the rods freely and the needle and seat operate properly.

Wet plugs, Hmmm. OK, let's go that direction. Have you determined if the plug wetness is oil or gas? Sniff test might do it, a burn test would work too. Have you checked to see if there is a strong spark at the plugs before and during the problem? If all is well with the spark (new plugs is a good idea) then it's on to too much fuel. SU's will run well with 3 - 3 1/2 psi. Anything over that can over power the needle and seat and overfill the float chambers. Did you re-set the floats when you rebuilt the carbs and what method did you use? That's enough for now. Keep the info coming. We'll get to the bottom of this.

I'm thinking that there's a couple of problems. 1st, if the engine won't pull a load but rev's freely when not under a load the problem is usually lack of fuel. There can be many causes. A fuel pressure and volume test is first. That should rule out everything up to the carbs. Check the filters in the banjo fittings above the float lids if you haven't already. Even with a poor fuel flow the engine should idle smoothly. Recheck the float levels, be sure the nozzles slide up and down easily when operating the choke and run thru the carb balancing-tuning procedure again. What color are the plugs?

IMHO, A weak spot just off idle is the nature of the beast unless it's so weak that it's a PITA.

Does the engine rev freely when not under a load?

When the problem starts, does the engine rev fine if it's not under a load? As in neutral or clutch in? Does operating the choke (plus or minus) make any difference?

Presumably you're using the choke when you start it. Does changing the choke setting, (plus or minus) have any affect when it starts to run lousy? Did any of the repairs, especially the carb rebuilds, make ANY difference, good or bad? What color are the plugs?

I was thinking about using Versimold to fill the voids that remain when using the squished heater hose.

Welcome. You've got a good start. Many of us didn't have the luxury of driving our Z home. We felt fortunate if it would roll. Starting the engine came much later. You'll have a lot of questions. You've come to the right place for answers.

Silicone rubber. Versimold is heat set. Sugru is air? dry. They're both about the consistency of clay. I don't know the hardness of either one but Versimold is the most economical of the two. Has anyone tried the pourable Flex- Seal?

Curious about something? In the video, when you rev the engine, was that an intentional slow rev? In other words, does the engine respond instantly when you give it throttle?

Any service manual or Phil's "Quick and Dirty SU Tuning" will show the screw. It's pretty easy to find by studying the linkage.

Welcome, Tell us about your project.

Pringle's Chips fall into that category too.

IMO, it's better to experiment with different wt. oils in each carb to achieve equality than reducing the oil level. Post #5 you mention using 30 wt. oil. I believe the F.S.M. calls for 20 wt. I use ATF. The red color makes it a little easier to see. The tops with the plunger rods should be snug.

As I recall, @Captain Obvious is one of the dash light LED guru's.

I already have it's twin, in yellow and yet another in orange.

Sounds normal.

Yeah but at least it's fine British engineered tape!

NOOOOOOOOOOOOOOOOoooooooooo