Stromberg BX illustrated

Stromberg BX

This carby was fitted to the Holden HX HZ, Torana LX UC and the VB Commodore all with the 2.8 & 3.3L 6 cylinder engines. Also fitted to the Ford Cortina TD TF and the Falcon XC XD with the 3.3 & 4.1L engines.

Throttle shaft wear is minimal so generally don't need replacing. Sometimes the lead balls (60) will leak fuel. If you can't get the lead, get a small sinker and use that instead. They are a bit harder and you need to use an appropriate sized nail punch to insert them. Anyway for the DIY rekit you would never remove the lead plugs in the first place, unless they were leaking. Only professional rebuilders do this to clean out the passages properly during a major rebuild not a simple re-kit. The video to the right covers most of what I have written below and possibly a bit more.

The following procedure is rarely needed on a BX series carburettor and in fact I personally have never had to do it but if the pump rod (5) has a lot of lateral movement in the body slot then a little panel beating to the edge of the slot is required. This is a rather crude way to fix it temporaraly but it works and lasts until the next re-kit. I use a pin punch about the width of the slot & give it a far hit from the side. Make sure the rod fits nicely & moves without binding. You won't get rid of all the lateral movement & I would advise you don't try to. All that will happen is the rod will stick & you will have to hit the rod laterally to undo the panel beat.

To test the power valve jet for serviceability, simply put it in your mouth to seal the head (pin towards your mouth) & suck on it. If you can draw in air the valve is leaking & needs replacing.

If you still have the original plastic insert for the mixture screw then set the top of the mixture screw about level with the top of the plastic insert as a start point.

There is a small welsh plug fitted in the power valve plunger. It will eventually pop out and will cause the power valve to stay on. The easiest way to fix this permanently is to fit a ball bearing in, just like in the pic.It will never come out again, ever but you must remove the welsh plug first.

The photo is not correct. The power valve plunger is staked into the air horn not screwed.

The fuel level setting is 5/8" to 11/16" below the top surface while the engine is running. This is a bizarre way to do it in my books, however this is the Holden way. Here is how I have done it from the beginning of time, statically on the bench during reassembly, never had a problem. Press the tang lightly against the needle, the float level should be set so that the top of the float is just off parallel ever so slightly to the top of the carby as shown to the left. Adjustment is done by simply bending the tang.

When you fit the accelerator pump plunger, dip it in petrol first or place a few drops of oil on the leather, then flare out the cup end. If you get a rubber plunger it can be fitted straight in. Fit the plunger into the bore using a circular motion so the cup slides in easier without getting caught. With most of the carby assembled less the air horn (3) put some fuel into the bowl. Test that the accelerator pump works as soon as the throttle is opened and the movement of the pump plunger is instant.