Zenith Enrichment Valve

[neilca]

I just bought a pair of Zentith carbs and noticed one carb has the enrichment valve in place while the other does not have an enrichment valve. The carb without the valve has all the required ports blocked with plugs.

Can anyone explain the function of this enrichment valve? For racing only applications would it be better to have the valve or remove the valve?

Thanks,
neil

[Wayne 962]

If I remember correctly, this is a cold-start circuit, and is designed to dump raw fuel "down the hatch" when starting. I believe that this was to blame for many engine fires, and thus, most people have blocked it off. Porsche went away from using carbs with this circuit after they had problems like these...

-Wayne

[Todd Simpson]

It's been a while since I've had Zeniths, but IIRC there is only one solenoid, then a line that runs over to the opposite carb so the one functions for both carbs.

I don't think they were for cold start, rather to cut off gas on the overrun to limit emissions? The T's had a switch connected to the throttle linkage just like the MFI's did.

There is a simple way to disable the system and it's not needed for performance.

[neilca]

Thanks guys,
That system is history! I love simplifying things.
neil