SSS carb rebuild kit? +advice...

[CaliforniaDays]

I have the SSS dual hitachi carbs on a 1600cc, my car recently is having trouble starting and I have reason to believe the carbs are leaking. Had to loosen my idle screw a ton to get my rpm's up 500 to get a steady idle, then my 510 won't start now, sounds like it's starving of fuel. Not quite sure what's wrong but before I dive in I'm curious on how much a rebuild kit would be on my carbs?? Any input is appreciated. Also: I plan on doing an engine swap of some sort, is the 1600 a decent engine for an early Z car/ 2-door 510?

[jvb5577]

Check the butterfly shafts.  If you can wiggle them up and down you will need new bearings installed.  You can also spray some carb cleaner around the bearings and if the idle drops then you know they are leaking.  There is someone who does it in Canada.. don't remember his name on here or there is Ztherapy.com 

 

I think Ztherapy.com charges over $300

[zerow]

The rebuild is easy on these carbs. But, before you get a kit or pieces,  I am going to put my money on the possibility that you have your mixture set incorrectly. 

[ggzilla]

Rebuild kit won't solve that problem.

 

Kit is much simpler than a downdraft kit. It has new gaskets and washers (but only solve external leaks), new needle-and-seat. Some kits include new needle, but it will probably be the wrong needle for your engine.

[ggzilla]

I have reason to believe the carbs are leaking.

What reason do you have? External leaks will be solved by new washers that come with the kit. Float level set too high or hole in float won't be solved by a kit. Leaking needle-and-seat needs replacement and comes with the kit (same needle-and-seat as downdraft Hitachi).

[ggzilla]

Had to loosen my idle screw a ton to get my rpm's up 500 to get a steady idle, then my 510 won't start now, sounds like it's starving of fuel.

That indicates a fuel blockage. Kit won't solve that, but a cleaning & tightening might.

[MikeRL411]

1- Change your fuel filter [at least once, you may need more].

 

2- You probably have a fuel bowl float problem. After 45 years strange things happen to factory original floats that the designer figured only had to last 10 years. The choice of "original" soldered brass versus "modern" poly plastic replacement floats is up in the air.

 

3- All the above failing, to check for bushing wearout, apply a little Dow Corning DC4 silicon grease to the spots where the throttle shafts exit the SU housing and filet a little with your finger. If this improves performance, then you need to find a local reputable [not ncessarily mutually exclusive choice, believe me] carb shop that is willing [the most important step] to take on the throttle shaft rebushing job.

 

Remember, once restored to OE performance baseline, SUs, especially Hitachi derivatives, are very reliable. I have had mine retuned twice in 47 years.