Originally posted by Seasalt; additions by T:
Bendix-Stromberg WW and WW-2 Carburettors:
How Do I Know if it’s the Right One?
The carburettor should have a parts code number on its body.
The first two digits of the code number gives the vehicle it came off - the 23 is Holden, the rest allows you to look up main jet, idle air bleed etc. A 23-201A&B is 186S Manual, a 23-202A&B is 186S Auto.
The earlier version for an HQ 253 manual is the 23-3046, & the later version (Nov '72 onwards) is the 23-3064. A ’73 HQ Premier 253 had 23-3063. The 23-3098 is for the 4.2 (253) V8 auto in HX & LX from July '76 to April '77. 3032 is tg 253 auto
Leyland P76 V8’s used them, and a number of American and British vehicles.
Construction:The Stromberg WW series are dual throat downdraft carbies. The top (air horn) gives the appearance of a single throat, but if you look down inside, you will see that there are two throats and butterflies.
The carburettor disassembles into:
1. The carburettor top or air horn, including economiser jet vacuum piston (or power valve), float vent, external choke diaphragm assembly, and choke butterfly.
2.The carburettor main body, including jets, float, accelerator pump, and vent.
3.The carburettor throttle body, including butterflies, idle adjustment, and automatic choke assembly.
4. The WW-2 carburettor has a throttle damper dashpot to cushion the closing of the throttle when the foot jumps off the accelerator.
The float chamber vents into the air horn, which has an opening where the accelerator pump is, that is open at idle. This opening is closed by an adjustable vent washer on the accelerator pump plunger as revs rise. There are two other small vents into the individual throats.
The automatic choke, I have seen disabled more times than not. It uses exhaust gas to heat a thermostat spring to open the choke butterfly as the engine warms.
The choke diaphragm is meant to vary this in some operating conditions.
The choke is pushed fully open by a cam if you put your foot to the floor. This is to clear excess fuel when flooded by too much accelerator pump-ing.
The “economiser jet vacuum piston��?, or what Holley would call a “power valve��?, provides extra fuel under low vacuum conditions. The economy bit is at part throttle or low load conditions when it isn’t operating…its ad-speak.
There are a couple of things to remember. Once you remove the carburettor from the manifold, the butterflies can protrude at the base, so don’t go banging it around on its bottom. Be careful with it.
Under one of the throttle body attaching screws is an air bleed restrictor wire. Do NOT lose it.
Clean the carburettor thoroughly. Check the parts for warpage (put steel ruler across machined surfaces and look for gaps), also look for burred edges, cracks, worn throttle spindles, moving part wear, and obvious defects.
If the accelerator plunger end has gone hard, it needs replacing.
Blow out all the jets and orifices with compressed air. (Special tool needed to remove jets.)
Its not considered a good idea to clean your jets with bits of wire, or other sharp objects, as it might do enough damage to upset the jetting.
If you can see a circle of wear around the needle part of the “needle and seat��?, its worn, and probably needs replacing.
Make sure you put the wire restrictor back when connecting main body to throttle body.
Don’t use any lubricant on the power valve, or it’s bore in the air horn (top).
When you get to the point where the top goes on next, it’s time to check the float level.
The distance between the top edge of the carburettor and the top centre of the float should be 4.762mm when the fuel level is correct. This can be adjusted by bending the tang that bears on the needle and seat.
When you do put the top on, don’t hold it crooked. You’ve got to lower it straight down, so that the accelerator pump lines up with its opening, and so that the vacuum piston stem doesn’t get jammed and also make sure the idle tubes line up……….
When you hook up the accelerator pump, unless you’ve got a good reason, hook it up to the centre hole of the three available.
If you have a dashpot model, they are meant to have a couple of millimetres between the plunger and the throttle cam.
There is no vacuum advance takeoff on the carburettor. Its usually on the manifold.
If you are fabricating your own throttle linkages, make sure you have Wide Open Throttle when the accelerator is Flat To The Floor. I’ve seen a few home made linkages that only gave half or three quarter throttle.
Exploded Diagram:  It needs to be expanded to the maximum size for print to be readable.
253/161S Jetting Comparison: