" basic settings first gen su " guidelines anyone?

[bartsscooterservice]

Are there any basic settings for the different adjustment screws? Was wondering.. since I have them of now for cleaning

Bart

[240260280z]

Lots of info in these sections of the forum:

SU Carb Technical Articles

SU Carb Discussions

Articles by our Members

Carburetor Systems (S30)

[Stanley]

All the above and/or the Factory Service Manual (or L24 Engine Manual). Also Ztherapy video. The FSM has a graph with mixture base settings from about 2 to 3+ turns down depending on temperature and altitude. Those settings go out the window if your needles/nozzles are worn out, or if your floats aren't set right (so you'd need to read the links above and do a real carb tune). Need a flow meter or experienced ears to set the balance screw. Same with high speed balance screw. Set the idle where you want it.

If you just want it driveable it's pretty easy; for maximum performance you also need a stopwatch, drag strip, or dyno (or an experienced Z car race mechanic).

[bartsscooterservice]

I did look at the articles, but the main problem with my carbs is the operating mechanism om the side of the carbs, that I think are somewhat wrong, if somebody has a detailed picture of that part for me? I can look how it's supposed to be..

1 carb when I operate the main throttle it will lower the nozzle just a bit, the other one doesn't lower the nozzle at all, something is wrong with the operating mechanism settings. Choke seems to work on both carbs.

[siteunseen]

I did a google "IMAGES" search and found one of the diagrams. Try that.

[Stanley]

The linkage on the side of the carbs is over my head, but I'd start by spraying carb cleaner followed by lithium spray grease on it. The nozzles aren't supposed to move unless you pull the choke.

[Gary in NJ]

1 carb when I operate the main throttle it will lower the nozzle just a bit, the other one doesn't lower the nozzle at all, something is wrong with the operating mechanism settings. Choke seems to work on both carbs.

The mechanism that moves the Nozzle is the choke actuator. The Throttle has no connection with the nozzle. When the choke is engaged it does open the throttle plate, but that is independent of the throttle linkage.

[bartsscooterservice]

aha ok I got it now, seems the same principle as CVK carbs. I will have a look at the carbs tomorrow, thanks

found this, helped me out understanding the carb

SU Variable Choke Carburettors Explained

Edited March 2, 2013 by bartsscooterservice

[ninjazombiemaster]

Probably some grime moving the choke linkage when the throttle is applied. I'd clean it until they move independently. Leaving it will goof with your carbs mixture on acceleration.

That image gives me a question, when might someone adjust #1: The Vacuum Adjusting Screw?

I also reference this image a lot. Its from a Volvo, so there are some minor differences, but the main workings are the same.

Not to hijack the thread, but my car has been seeming to "run out" of fuel on very heavy acceleration - as you might see going up a freeway ramp (or every stoplight ever ) If I keep the pedal heavy pressed, it makes a sputtering sound, loses power, backfires majorly and then picks back up when I shift.

I'm guessing its either running a little rich (depleting the bowl faster than it could fill) and flooding until it clears and, then boom. Possibly the bowls are just set too low, as well. And it runs out. Doesn't explain the boom, though.

[Travel'n Man]

Probably some grime moving the choke linkage when the throttle is applied. I'd clean it until they move independently. Leaving it will goof with your carbs mixture on acceleration.

That image gives me a question, when might someone adjust #1: The Vacuum Adjusting Screw?

I also reference this image a lot. Its from a Volvo, so there are some minor differences, but the main workings are the same.

[ATTACH=CONFIG]61557[/ATTACH]

Not to hijack the thread, but my car has been seeming to "run out" of fuel on very heavy acceleration - as you might see going up a freeway ramp (or every stoplight ever ) If I keep the pedal heavy pressed, it makes a sputtering sound, loses power, backfires majorly and then picks back up when I shift.

I'm guessing its either running a little rich (depleting the bowl faster than it could fill) and flooding until it clears and, then boom. Possibly the bowls are just set too low, as well. And it runs out. Doesn't explain the boom, though.

Before touching a thing on your carbs I would advise you to read - read - and read some more on your carbs. There is no magic fix for SU's - it takes everything working together in unison for your SU's to be spot on. Personally, I would ditch the above diagram and get the correct diagram for your carbs. Once you have read and understand the workings of your SU's then the fix is very easy to implement and correct.

[ninjazombiemaster]

Before touching a thing on your carbs I would advise you to read - read - and read some more on your carbs. There is no magic fix for SU's - it takes everything working together in unison for your SU's to be spot on. Personally' date=' I would ditch the above diagram and get the correct diagram for your carbs. Once you have read and understand the workings of your SU's then the fix is very easy to implement and correct.[/quote']

I feel like I've got a pretty good understanding. I've got the ztherapy video, and have recently rebuild them myself. I myself haven't found an exploded Z SU diagrams, so that's just the next best reference when trying to understand the mechanism, right after taking it apart. But in the scheme of things I'm pretty new to this, and reading has not compared to the first hand advice from more experienced members here

[240260280z]

This thread shows how to reassemble SU's with lots of photos and exploded drawings.

http://www.classiczcars.com/forums/articles-our-members/43176-su-reassembly-step-step-%5Bpart-1-tear-down-torn-n-tattered-worse-wear-n-tear%5D.html

Edited March 4, 2013 by Blue