One of the most important pieces of information I ever received about cars came from a close friend and mentor. He told me, “These are all crap and they all break.” While that’s a pretty grim way of putting things, it reflects years of professional experience tinkering with everything from passenger cars to quarter-mile monsters , meant it was the gospel.
This is especially true for carburetors. They’re archaic, raw, smell bad and I love them. Maybe you too. But if you’re running a carburetor, you’ll have to tinker with it at one point or another. That doesn’t mean you have to be a carburetor wizard. You just need to know the basics of maintaining and repairing it after it breaks.
One of the more involved processes in carburetor servicing is cleaning. No matter how primitive they are, there is a lot going on inside. However, all passageways, openings, cavities and crevices have one thing in common: They love to collect dirt. So today you have The ride‘s Mega Minds to show you how to clean your carburetor.
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Basics of carburetor cleaning
Estimated time required: 1-2 hours
skill level: Intermediate
Cleaning carburetors isn’t the most dangerous of routines, but some OSHA officials are sure to squirm in the process. Nevertheless, you should definitely wear your protective gloves and safety goggles. We’re not just saying this to avoid possible lawsuits. Carb cleansers are powerful chemicals, and they will do more than just clean your skin and eyeballs – trust me, they will find those eyeballs.
You should also really make sure you’re working in a well-ventilated area. If you keep the doors and windows closed, you will almost certainly feel a little light-headed. And when you fancy a cigarette, do your best to keep the open flame away from the gasoline and chemicals you’re dealing with. You are not the Human Torch, you are being burned.
Everything you need to clean carburetors
Does a carburetor cleaning really cost $50-$100? no But that’s just a formality. The reality is you’re probably spending $25-$50 on cleaners depending on how much and what type you need. We’re saying you’ll end up investing $100 because you should at least get a conversion kit, too.
Cleaning the carburetor and overhauling go hand in hand. Going through it and making sure all the internals are in order will only help you get more out of the work you’re already doing. Plus, all those bits will come out and you’re bound to rip a few gaskets in the process. You are not adding any more time to the process by replacing them.
So what will you need? While a can of carburetor cleaner will do wonders, it’s just a tool for the job. You should use a chemical bath to get into those extra deep nooks and crannies. Kitchen towels, a brass brush and some wire will also come in handy. Get a cheap oil pan and you’re in business.
Carburetors are complex, but you don’t need much more than a few simple hand tools to disassemble and reassemble them. A set of screwdrivers, wrenches and needle nose pliers should all be available. Depending on the carburetor you are working with, some specialty tools for removing jets, power valves, etc. may be desirable. It’s important to do the homework in advance to determine whether or not it’s necessary for the model you have.
How to clean a carburetor
1. Remove the carburetor from the manifold
Of course you can use it to clean parts of the carburetor on the manifold, but you can’t get everything right. Also, you are likely to drop something while you are working and suddenly you have a big headache on your hands. Be sure to stick a clean rag into the manifold to prevent dirt or debris from falling into the open cavity.
2. Drain the fuel
It’s a good idea to remove all fuel from the carburetor before disassembling it. Some choose to turn the carburetor upside down and allow the fuel to flow into a catch tank. You can also hit the gas a few times to speed things up.
3. Tear off the carburetor
The disassembly process varies by carburetor model, making it difficult for us to give you an exact procedure to follow. However, we can tell you to keep track. Examine each piece you remove and take notes on where it goes. Jets, metering rods, power valves, exhaust jets, etc. should go back exactly where you removed them.
4. Take care of the big bits
You should take the time to clean any heavy deposits from the carburetor parts before dropping them in the chemical bath. Your brass brush combined with some carb cleaner is all you need for these bits. The chemical bath can get rid of these deposits, but you’ll only add more time to soak each part and shorten the life of the product if you don’t take care of it beforehand.
5. Time for a bath
After most of the dirt has been removed you can move on and start lowering each one for a bath. Each part should soak for about 20 minutes to half an hour. You can work in batches to speed things up.
If your parts are too big for the container your bath comes in, you can turn your drain pan into a bath. Just make sure you open more doors and windows. You cannot expect the best results with this method as the parts may still not be fully submerged – this is exactly the problem I encountered when attempting to soak the main body of my Holley 4150.
6. Spray and scrub
The chemical bath works wonders, but it can only do so much. After the parts are removed from the solvent, you should apply some elbow grease. A clean brass brush and some carb cleaner is the recipe for covering larger areas that still have deposits.
7. Fire in the Holes
Now for the fun part. Carburetors are filled with all sorts of passages that are as dirty as the spots you can see. You have to go in there. You can also use carburetor cleaner on this part. I like blowing carb cleaner through the passages and watching if it comes out where it’s supposed to. If not, then there is a blockage that you need to clear with the help of a thin wire. Just make sure your eyes aren’t in the line of fire while spraying carb cleanser in all passages, as its onset can be an unpleasant surprise.
8. Clear the jets
The jets in your carburettor are prone to deposits. Thankfully, there’s no guesswork. All you have to do is hold the jet up to make sure you can see through. Handling gunk is made easy with a thin wire or drill that fits snugly in the hole. Never use a drill to remove clogs as you may damage or enlarge the opening.
9. Reassemble the carburetor
Once everything is clean you can proceed to reassembling the carburetor. However, what’s the point of throwing dirty old parts in that squeaky clean carburetor? Rebuilding protects your efforts and ensures carbs are factory fresh and ready for anything!
Carburettor cleaning video tutorial
Sometimes pasting things into text tends to complicate some things. Although we do our best, we understand that we are not there to accompany you physically. However, we can connect you to a video tutorial. This bit covers motorcycle carburetors, but the basic principles apply to virtually every other carburetor out there!
frequently asked Questions
Getting started in the world of carburetors is bound to raise questions. Don’t worry. We have answers!
Q: What’s the best way to clean a carburetor without disassembling it?
A: The short answer is you can’t. There are additives you can try running through the fuel system, but the fact is you cannot rely on them to deal with stubborn deposits or deposits that are typically found in a carburetor. It’s best to take it apart and make sure everything is clean with special solvents and chemicals.
Q: How do I know if my carburetor needs cleaning?
A: Many signs can tell you it’s time to clean a carburetor. Flooding or fuel spurting out of the fuel tank vents, rich operating conditions, lean operating conditions, or the engine not running can all mean the carburetor needs scrubbing. It is best to look for such problems that you cannot solve with standard means by adjusting the carburetor settings.
Q: How do you rebuild a carburetor?
A: Rebuilding a carburetor can be as simple as replacing the gaskets and overhauling all major components. Precisely for this reason, you can also carry out a conversion during the cleaning. The process varies depending on the model of carburetor. We cover the rebuild of a Holley 4150 Double Pumper to give you an inside look at the process.