How To Overhaul A Stromberg Carburetor

How To Overhaul A Stromberg Carburetor?

If you’re a vintage car owner, this article is especially for you. Whether it’s Lincoln or Ford, the Stormberg carburetor was a manufacturer favorite in the earlier days. However, you’ll rarely find this carburetor on newer models in today’s day and age. Due to this reason, many mechanics aren’t aware of how to repair this carburetor. A Stormberg carburetor requires overhauling at regular intervals to stay properly functional. Therefore, this article will tell you how to overhaul a Stormberg carburetor. From teaching you how to reassemble the dashpot and piston to how to dismantle a float chamber, read this article to learn everything, you need to know about a Stormberg Carburetor.

Why overhaul a carburetor?

When a car’s engine goes on a long time without running, it starts developing problems. Consequently, this harms the car’s carburetor as well. When gasoline evaporates and causes blockages in the carburetor’s orifices, the engine ultimately dies. Thus, a carburetor overhaul must be performed to tackle this issue.

What is a Stromberg carburetor?

A Stromberg carburetor is a type of carburetor that accurately delivers fuel and avoids unnecessary icing in the carburetor. It also eliminates the inlet valve and hinders inverted flight and fuel starvation in a car.

How to overhaul a Stromberg carburetor

Now, let’s dive straight into how to overhaul a Stromberg carburetor. Firstly, you don’t need to regularly service a Stromberg carburetor. However, it should be clean at least once every year. Furthermore, all worn-out parts should be replaced when necessary. Dirt tends to penetrate through the fuel filters. This dirt, along with chemical residuals, accumulates inside the carburetor. In addition, the jets and needles become worn out after some time too.  

There may also be holes in the rubber diaphragm. These holes can reduce engine power. In addition, if the holes become too large, the engine will become unable to idle. Clean the carburetor after removing it. Avoid the petrol from spilling by keeping the carburetor straight and then emptying it. Clean all the components with petrol. However, don’t rinse the diaphragm.

Dashpot and piston

The piston chamber’s top is referred to as the dashpot. Remove the damper by unscrewing it from the dashpot. Then, pour away the engine oil that’s inside— mark the dashpot’s position so that you can place it back properly. Then, take the piston out carefully.

The diaphragm will also remove when you take the piston off, as it can be torn easily. Make sure you do not hurt the needle while lifting the needle out.

After you reassemble, use multigrade engine oil to fill the dashpot. Fill it a little beyond the brass piston’s level.

Jet Needle and Diaphragm- Replacing

If the carburetor’s needle has worn out, it will have a groove. A weary jet needle will hinder the engine’s optimal performance and thus must be replaced regularly. Jet needles come in many sizes, so check if you’re getting the right one. Loosen the grubscrew placed on the piston’s side to remove the needle. Now, unscrew the retaining ring to remove it. Then, lift both the diaphragm and the retaining ring.

Float chamber- Dismantling

Use pliers to detach the adjustor and stop the jet before removing the float chamber. Remember that models with emission control systems don’t have this stop. Connected via six screws is the float chamber. Take them out. Now, lift off the chamber but be wary of the sealing ring. Pull it out carefully. The float might get damaged if you jerk. So, don’t jerk it. Pull the float pin out once the chamber is removed.

Older models come with a pin that can be easily removed using bare hands. Use a screwdriver and gently tug it out in case it is stiff. Models with emission control systems come with clips made of pins that can be taken out easily using a screwdriver.

 Fixed in the float chamber’s base using screws is the float needle valve. You cannot dismantle it. You will have to replace it if it wears out or gets blocked.

Float Adjustment

Learning float adjustment is an important aspect of learning how to overhaul a Stromberg carburetor. A faulty or leaky carburetor float can cause flooding. If you find fuel shaking inside it on shaking it, it hints towards a leaky float that needs adjustment. In case of adjustment doesn’t fix the problem, you will have to replace the float.

Turn the carburetor upside down. Now, note down the float’s height above the body’s edge. A hollow float should have a height of 16 mm to 18 mm, whereas a solid float must have a height of 18.5 mm to 19.5 mm.

The tag touches the needle valve. Bend it to adjust the float. Invert the carburetor and measure the height of the float beyond the body edge. Lastly, adjust the float’s height by bending the tag.

Jet removal

Do not remove an emission control model’s jet at all costs. It has a castellated adjuster nut which needs a unique adjusting tool for its adjustments. Don’t turn the nut, or else you’ll disturb the mixture. First, wash it using petrol, thus cleaning it while it’s still in place. Then, use a foot pump to blow it.

The next step is to unscrew the holder and remove the jet. Use a spanner to unscrew. Don’t tamper with the jet adjusting screw to avoid altering the mixture.

Now, pull the jet out by lifting the jet holder. Then, rinse the jet using clean petrol and clear it via a foot pump.

Wrap a rubber ring around the jet holder. Check it for signs of wear and tear. A faulty ring will have a leaky float chamber. Without scratching the surface, take the ring out using a screwdriver. Finally, wrap the holder using the new ring.


Learning how to overhaul a Stromberg carburetor is one of the best skills to learn for a vintage car holder. This is because older models of cars tend to develop issues while starting and overhauling will help you mitigate this problem to a great extent.

In a nutshell, a vintage car is like a baby. Thus, who better to take care of your child than yourself. This skill won’t just save you tons of money but will also teach you the art of car maintenance (Learn about maintaining your car and its underside on The Importance Of Cleaning And Checking The Underside