OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines 2 needle or 1?

According to the Identify you Victa, I have a powertorque.
Is this a 2 needle or one needle carburator assembly, so is there one or two screws that could be adjusting the mix?

On a victa 2 stroke with a plastic carb there is no adjusting the mix as it is permanently set, there is one jet and that is the screw that holds the primer cover on

But the brass-coloured screw (thats a jet, right?), if I turn that anticlockwise, it stalls the engine. What do I do with that than? Its now all the way clockwise, anything more anticlock will stall the engine.

Yes, that screw is the jet, But it's a fixed jet, when you turn it anti clockwise, the engine will eventually stall, this is because you have removed the jet, and fuel cannot get through.

It should be as tight as needed to secure the face onto the carburettor, but not stress the metal.

What are you trying to achieve here, there is no mixture adjustment screw on these carby's, but if there is issues, they can be fixed.

No real issues, just trying to get to known my two stroke. Keen to know how it works, thats all. And therefore trying things out.
The original question was regarding increased fuel loss, I got some advice on that already.
So, just out for knowledge...and the experience of the forum helps quite a lot with that

No worries mate.

When the jet is loosened, it prevents vacuum from the intake pulling fuel through the jet, as the seal around the jet is broken, and air is simply pulled through instead.

Rev's can be adjusted in 3 ways:

1) Some models have an adjustable poppet inside the carburetor with the letters a, b and c on it, for most mowers it should be set to c.

2) Over time, the inside runs of the carburettor can wear out a little, this will cause increased rev's, to rectify this, a very small brass washer can be fitted to the central post inside the carburettor, below the throttle rotor.

3) On the throttle control/air filter you will see a small Philip's head screw at the point where the hose connects, this can be loosened, and moved up and down for minor adjustment, it should be set so that when the lever is pulled to the stop position, there is a matchstick width between the lever, and the end of it's running slot.

Rev's can also be affected by air leaks, at the bayonet carby mount o-ring, at the intake port o-ring, and the o-ring where the starter meets the engine block, also, muffler blockages, damaged head gaskets and problems with the decompresser operation can effect performance too.

The carburettor is essentially a pre-set unit, it is governed by a vacuum feed from the flywheel when in the "run" position, and pre set to "choke" in the start position, when in the stop position, 2 contacts are connected, shorting the ignition system.

You can find more detail about the construction and operation principals of the carburettor in the manuals section.

Technically you can adjust the jetting of the Victa.

Its the first rule in the basic principal of a Carburettor, the fuel height effects everything.
So techincally by adjusting the float height in a victa (either by swapping needles or turning the primer face) you can adjust the jetting.



I would say that if your fuel economy has worsened since you did something on the machine you need to go over what you did again.