jonbill

I got it all right. But the one about pure, high quality liquid or gas was annoying.

That's a really boring video.

Sounds like there's something odd about cylinder #6. If the overall engine is lean, is 6 so lean its missing and fouling, or is it oil fouling? Where does the master vac take its vacuum from on this setup?

OK, they're cool. Never mind me. :)

Which NGK? BPR6ES?

Those old spark plugs look quite cold, colder than standard which would contribute to fouling at idle. What plugs are the new ones?

I think you've got a few things need fixing. First up is a big air leak that's making the mixture lean and causing revs to rise. Either the throttles or chokes are open, or the carb to manifold or manifold to head gaskets aren't sealing.

That's true with the Kameari damper too. I clearanced the back of the fan blades by about 1mm to miss the damper. I couldn't space the fan forward because my fat radiator is in the way.

I stand corrected. It works fine on the Kameari damper :)

IIRC, your engine builder used the Kameari crank damper bolt and washer Ali.

When you step on the gas, is that going full throttle from low revs? How does it handle progressively opening the throttle from higher revs?

http://www.edproject.co.uk/NarrowAFR.html

Bkr7e seem the best compromise on mine. Doesn't melt at high revs, doesn't foul at idle. It's a 14mm hex because my plugs are 5mm further in than normal.

At least you've got one working one to compare too, and a good book. On my Dellortos the problem with the accelerator pumps is always the one way valve gets gummed up if the carbs aren't used for a while and sit with fuel in them.

There might also be throttle stops per carb. This is a good book on setup. https://www.amazon.co.uk/gp/aw/d/1845849590/ref=dbs_a_w_dp_1845849590 I'd start with making sure the throttles are closed at rest and adjust the linkages so all 3 throttles start to move at the same time. Idle mixture screws I think should be a couple of full turns out from fully closed (but not sure of this, I don't have Webers). Have a look down the bore of each choke in turn as you open the throttle briskly and you should see a squirt of fuel going toward the engine. (3 pumps should be plenty for cold start even without choke, too many pumps will flood it). If the carbs are reasonably assembled and no big air leaks at manifold it really should start like that.

The left one is for the crank case ventilation pipe (although it looks small in that photo? ) and the one on the right is the block coolant drain. It should be just plugged in normal use. (although I have see one with a secondary electric pump extracting from there)

Imperial and US ounce are the same I think. Wiki agrees https://en.m.wikipedia.org/wiki/Ounce I think we just deviate on how many ounces are in larger units like pints and gallons. An ounce is 28.3 g, so 24oz is 679.2g

If the colour of the plugs is OK, and it really is backfiring through the inlet, I'd suspect the ignition timing.

+1, they definitely have to be in the diff first, and it's much easier to do it while the diff is on the floor out of the car.

There's an explanation of Z7 here: https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=4017 I liked it better when there was some mystery.

Kameari sell larger valves. I'm sure many others do too, but I like Kameari stuff. https://www.rhdjapan.com/search/engine/nissan_fairlady-z_s30-l28-10-1971-08-1975/model/nissan_fairlady-z/car/nissan/category/cylinder-head-and-valvetrain_valves

I'd agree. Definitely get a decent pump, get a decent regulator and see if you've still got a problem or not. If there's still a problem, at least you'll be sure where the problem isn't.

I've used Holley Red and Blue pumps and I found them both ferociously loud and rather unreliable (correctly positioned at the level of the bottom of the tank). I wouldn't recommend them. I'm currently using an old quiet Bosch 4 bar diesel pump out of my BMW. I've got an Aeromotive FPR that regulates it down to 2.5 psi and I'm very happy with it. I haven't read the whole thread but I read the first post and I'd say if it's going lean almost immediately at 3k in 3rd when you apply load, I don't think it's the fuel supply, it would take a few seconds to use up the float chambers. I think your needles are too lean. Are they the ones that came with the carbs? Apologies if you've been over this.

I use a length of box section bolted to the block to lock the flywheel:

[emoji102]