If you're staring at a greasy hunk of Italian-designed metal on your workbench, having a solid Weber 32/36 carburetor diagram handy is going to save your sanity. These carburetors—specifically the DGV, DGAV, and DGEV series—have been the go-to upgrade for four-cylinder engines for decades. Whether you're working on an old BMW, a Toyota pickup, or a classic MG, the 32/36 is a legendary piece of kit. But, like any mechanical marvel, it can be a bit of a jigsaw puzzle once you start taking it apart.
The beauty of the Weber 32/36 is its progressive design. Unlike a "square bore" carb where all the barrels open at once, this one is built for both fuel economy and a bit of a kick when you mash the pedal. You've got a 32mm primary barrel for your everyday cruising and a 36mm secondary barrel that kicks in when you need to pass someone or just want to hear that distinct induction roar. Understanding how these two sides interact is much easier when you can visualize the internal passages through a diagram.
Why You Actually Need a Diagram
I know, we all like to think we're smart enough to remember where that tiny spring and that specific washer went. But trust me, three days later when the new gaskets finally arrive in the mail, your memory won't be as sharp as you think. A Weber 32/36 carburetor diagram isn't just for putting things back together, though. It's also your roadmap for troubleshooting.
If your car is stumbling off the line, you might be looking at a clogged accelerator pump nozzle. If it won't idle, maybe there's some junk in the idle jet. Without a diagram, you're just poking around in the dark. The diagram shows you exactly where the fuel flows, from the moment it enters the fuel inlet to the moment it gets atomized and sucked into your intake manifold.
Breaking Down the Main Components
When you look at an exploded view of a 32/36, it can look pretty overwhelming. There are dozens of tiny parts, o-rings, and screws. However, you can usually break it down into a few main "neighborhoods."
The Top Cover (Air Horn)
The top of the carb is where the air enters. This part holds the float assembly and the needle and seat. If you're looking at your Weber 32/36 carburetor diagram, you'll notice the float is suspended from the top cover. This is a critical area because the float level determines how much fuel sits in the bowl. If it's too high, you'll flood; too low, and you'll starve for gas when you're leaning into a turn or accelerating hard.
The Main Body
This is the "meat" of the carburetor. It houses the primary and secondary venturis, the jets, and the emulsion tubes. This is where the actual magic happens. On your diagram, you'll see the primary and secondary jet stacks. One of the coolest things about Webers is how easy it is to swap these out. You don't even have to take the carb off the car to change the main jets or air correctors. You just pop the top off, and there they are.
The Throttle Base
At the bottom, you've got the throttle plates (the butterflies) and the linkage that connects the two. This area also houses the idle mixture screw and the idle speed screw. If you're trying to get your car to pass an emissions test or just want it to stop vibrating at red lights, this is where you'll be doing most of your work.
Understanding the Progressive Linkage
One thing that confuses people when looking at a Weber 32/36 carburetor diagram is the secondary linkage. Since this is a progressive carb, the secondary barrel doesn't just hang out and wait for a vacuum signal like on some older American carbs. It's mechanically linked.
When you push the gas pedal about two-thirds of the way down, a little lever on the primary shaft catches a tab on the secondary shaft. It's a very clever bit of engineering. The diagram shows how these springs and tabs interact. If your secondary isn't opening, or if it's sticking open (which is terrifying, by the way), the diagram will show you exactly which spring might be hooked up wrong or which shim is missing.
The Mystery of the Jets and Emulsion Tubes
If you really want to get into the weeds of tuning, you have to talk about the jets. On most Weber 32/36 carburetor diagrams, you'll see labels for the main jet, the air corrector, and the emulsion tube. These three parts work together to control the air-fuel ratio across the entire RPM range.
- Main Jet: This controls how much fuel gets into the mix at mid-to-high speeds.
- Air Corrector: This sits on top of the emulsion tube and "bleeds" air into the fuel. It keeps the mixture from getting too rich as the engine sucks in more air at high RPMs.
- Emulsion Tube: This is a brass tube with holes in it. It pre-mixes the air and fuel before it hits the venturi.
It sounds complicated, but once you see the cross-section on a diagram, it makes total sense. You can see how the fuel travels up from the bowl, through the main jet, and into the emulsion tube.
Troubleshooting with Your Diagram
Let's say your car has a "flat spot." You're driving along, you step on the gas, and for a split second, the engine just dies before picking back up. That's usually an issue with the accelerator pump. Looking at the Weber 32/36 carburetor diagram, you can trace the path from the pump diaphragm through the check valve and out the pump nozzle (the "S" shaped tube hanging over the primary barrel).
If that nozzle is pointed in the wrong direction or the diaphragm has a tiny tear in it, you're going to have a bad time. The diagram helps you ensure that every little ball bearing and spring in that pump circuit is in the right place. Believe me, losing one of those tiny check-valve balls is a rite of passage for every shade-tree mechanic.
Tips for Using a Diagram During a Rebuild
If you're planning on doing a full rebuild, here's a bit of advice from someone who's done it more times than I'd like to admit. Don't just look at the diagram on your phone screen. Print it out. Print it out big, and maybe even laminate it if you're feeling fancy. You're going to have greasy hands, and trying to pinch-to-zoom on a PDF while holding a screwdriver is a recipe for a dropped phone.
Also, as you take things apart, lay them out on a clean white rag or a magnetic tray in the same orientation they appear on the Weber 32/36 carburetor diagram. If the diagram shows a screw on the left, put it on the left of your tray. This "spatial memory" combined with the visual aid makes reassembly a breeze.
Another pro-tip: take photos of your specific carb before you start. While the diagram is great for showing where parts go, it doesn't always show how your specific throttle cable or return spring was hooked up by the previous owner. Sometimes people get "creative" with their setups, and you'll want a record of that before you tear it all down.
Common Mistakes to Avoid
Even with a perfect Weber 32/36 carburetor diagram, people still trip up. The most common mistake? Over-tightening the nuts that hold the carb to the manifold. These carbs are made of a relatively soft zinc alloy (Zamak). If you crank down on those nuts, you can actually warp the base of the carb. Once that happens, you'll have a vacuum leak that no amount of tuning can fix.
The second biggest mistake is getting the primary and secondary jets swapped. They look identical from the outside, but they have different numbers stamped on them. Always double-check your diagram and the numbers on the jets before you drop them into the holes. The smaller jet almost always goes on the primary side.
Wrapping It Up
At the end of the day, the Weber 32/36 is one of the most rewarding carburetors to work on. It's logical, it's mechanical, and it provides a huge boost in drivability over most stock setups. Whether you're chasing a smooth idle or looking for that extra bit of power on the highway, having a Weber 32/36 carburetor diagram in your toolbox is the best way to ensure your project is a success.
Don't be intimidated by the number of parts. Take your time, follow the lines on the drawing, and remember that these things were designed to be serviced. Once you get it dialed in, you'll realize why people have been obsessed with these little carburetors for over fifty years. Happy tuning!