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Got a question for you I have The su carbs on my z-car right now but they are way out of adjustment I have the richness adjustment approx 2 to 2 1/2 turns out and Ive sync the carbs my problem is I can back out my idle screw completly out and my idle will not go down if I adjust my carbs using the two screws that i used to sync them lower I can now use the idle adjustment screw
(hope I havent lost any you yet...)Now I have no power The car sneezes out the intake and bogs while i push on the gas.....Please if you know what I can do please e-mail me back.....P.S. the cam that is I the car is a 512 300 dur ....

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> Got a question for you I have The su carbs
> on my z-car right now but they are way out
> of adjustment I have the richness adjustment
> approx 2 to 2 1/2 turns out and Ive sync the
> carbs my problem is I can back out my idle
> screw completly out and my idle will not go
> down if I adjust my carbs using the two
> screws that i used to sync them lower I can
> now use the idle adjustment screw
> (hope I havent lost any you yet...)Now I
> have no power The car sneezes out the intake
> and bogs while i push on the gas.....Please
> if you know what I can do please e-mail me
> back.....P.S. the cam that is I the car is a
> 512 300 dur ....

> Thank you

First of all, what are you doing with that cam and stock carbs? Anyway, there are three idle adjusting screws on the SU setup. One on each carb and the fast idle screw at the top of the linkage. What I do to sync them is start with the fast idle screw. Turn it in so that the motor runs at about 2000 rpm. Then sync the carbs. Then let it idle back down to normal and sync the carbs using the idle speed adjusting screws at each carb. Don't reset the carb balance screw! Then, the carbs are sync'ed. As far as mixture, it sounds like you are way too lean. With that big a cam, you are going to need major fuel. I don't know what other mods you have, but mixture setting is somewhat trial and error. If I were you, I would start with the mixture screw out 3 turns. Then check your spark plugs every so often and adjust accordingly. You may even need different needles and emulsion tubes with your motor. They are available at your local Nissan dealer. If that doesn't solve the problem, try a smaller cam or go to the tripple Weber/Mikuni setup. Good Luck!!!!!!!!!! [email protected]
 
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