Today you will learn about some old technology that some people may have heard about but do not know how they work. Carburetors used to be the only way combustion engines would run before we had electronic fuel injection. Carburetors are a mystery to some people and have to be treated as an art. However, when broken down, they are super easy. Cleaning them can give you an understanding of how they work. You can find most carburetors in motorcycles but after 2012, manufacturers are switching to more efficient fuel-injected systems. However, if you have a carbureted motorcycle, I will show you how to clean it to run smoother.
The supplies needed could vary depending on the type of carburetor but a simple set of Philip and flat-head screwdrivers and a few wrenches is all that is needed for tools. Carb cleaner, paper towels, and a catch tray will also be needed for cleaning the carburetor.
Step 1: Loosening the Carburetor
Take the carburetor off the motorcycle. This step could have different steps depending on what system the bike manufacturer used to attach the carburetor. There could either be hose clamps or a few nuts and bolts holding the air filter side and the cylinder side. In my demonstration, we will have both styles. start to unscrew the hose clamp from the air filter. This should only need a few rotations to become loose. Next, unbolt the carburetor from the cylinder head.
Step 2: Removing the Throttle Cable and Gas Line
Now that the carburetor is loose on one side, repeat for the other side. This will require the same steps as the first carburetor. Next, we will unscrew the throttle cables from the top of both carburetors. This is done by simply unscrewing what looks like a cap on top of the carburetor and pulling the cylinder slides out from the top. Take the gas hose off the petcock for both carburetors and take them both out.
Step 3: Draining the Bowls
Next, unscrew the drain screw of the bowl to drain the gas out. The bowl might be empty depending on how long the motorcycle has sat. Drain the gas into some catch container to recycle to old gas correctly. Once the bowls are drained, place both carburetors on a flat workbench with room to lay pieces out.
Step 4: Remove the Bowl
Start by placing something down on the worktable to soak up any leftover gas that is in a passageway. Next, we will take the bowl off. This can be done by either a snap clamp or by screws. In this example, we must undo the snap clamp. Pry the clamp off the bowl being careful to not drop the bowl. If the bowl does not come off, grab a screwdriver, and start to slowly work the bowl side to side to loosen the gasket that is holding the bowl on.
Step 5: Removing the Float and Needle
Next, inspect the inside of the carburetor for large amounts of corrosion or damage. If there is damage, a replacement kit will need to be ordered. In this step, we will be taking the float out along with the fuel needle. Flip the carburetor upside down and locate the pin that is holding the float on. Pull the pinout and grab the float, then place off to the side. Go back and grab the needle that is in the hole that the float was covering. This may require flipping the carburetor around or using the plyers to pull it out. Place this needle next to the float to remain organized on the parts.
Step 6: Removing the Jets
Flip the carburetor upside down again and take the jets off. This will require a screwdriver. Unscrew both jets that are in the middle of the carburetor keeping track of which came out of each hole. This should be everything we will need to take apart inside the carburetor.
Step 7: Removing the Screws
Next look at the outside of the carburetor. There will be two screws, one will be sticking out further than the other. These screws control the air and fuel mixture in the carburetor. We will unscrew them to open the passageway up to clean. Make sure to dig out the springs inside the holes.
Step 8: Cleaning
Now spray each hole with carb cleaner. Make sure to hold a way to avoid spray back in case a passageway is clogged. Once each hole allows cleaner to pass, turn to the screws and needles we took out of the carburetor. These will have tiny holes that need to be clean to allow air or gas to pass through them. You can soak the parts in carb cleaner or spray down the parts till clean.
Step 9: Rebuilding
The final step is to start to replace the screws and needles in the reverse order we took them out. Start with the screws by screwing them in till they bottom out and then unscrewing them 1.5 turns. Next, screw the jets in until they are tight. They do not need to be super tight causing them to strip. Next, replace the needle that the float covers up. Make sure to not place upside down. The part with a little rod will be facing out towards the float. Next place the float and the pin back to the original spot. A new gasket may be needed if the old gasket ripped while taking it out. Place the gasket into the grove and place the bowl back on top. Snap the clamp back over the bowl completing the carburetor.
Step 10: Bolting Back to the Motorcycle
Repeat the disassembling and cleaning steps for the other carburetor. Now secure the carburetors back to the motorcycle in the reverse steps they came off. Once everything is back together on the bike, turn on the gas and look for leaks. If no leaks, the job is done. If a leak does occur, turn the gas off and trace down where the leak is coming from.