Page created by T Dec 31st 2010:
 Varajet Carburettor:
The Varajet was fitted to WB, VC and VK Four and Six Cylinder Holdens.
 Varajet Tuning:
Ok found this in some old notes....
If the idle mixture screw has had the seal tampered with for adjustment (they are factory sealed)and is preventing the engine from idling correctly it is possible to restore the base idle by turning the air bleed mixture screw in all the way until it seats. Having done this, adjust the throttle stop screw until the engine is idling at between 450 and 500 rpm.
Using the air mixture adjusting screw, slowly increase the engine idle speed to approx. 800 rpm, making sure not to touch the throttle stop screw. Finally, raise the idle to approx. 900 rpm, using the idle mixture screw.
Now, something I neglected to mention before, but also found reference to, the Choke is a vital component for the operation of the secondaries, they will not open unless the choke is completely off, along with the correct operation of the vacuum brake, these have both exactly the same operating conditions in the quaddy as well.
Start with that guys and see how you go.
Truelly, too many people junk these carbies becasue they do not understand them, which is a shame really...
 Vacuum Break:
One more thing to add, is in regard to the vacuum brake on the secondaries, in exactly the same way that the quaddy works, if the diaphram on the secondary vacuum brake is broken or in operable, it will use heaps of fuel, because as soon as the secondaries open, the vacuum brake will open up fully and deliver the maximum metered amount of fuel instead of using the airflow to meter the amount of fuel delivered.
IE. the vacuum brake has a metering rod within the jet to vary (vara-jet) the amount of fuel delivered.
These carbies, when operating at their best, will out perform the weber, both in fuel ecconomy, and power, hands down.
There is also an adjustment on the diaphram to vary the speed in which the vacuum brake opens, faster= more power and more fuel use, slower = well you get the picture..