How to Clean Motorcycle Carburetors
A clean carburetor will get your engine running better, eliminating problems like rough idling, bogging down, sluggish performance, and other problems caused by a dirty carb.
Deposits that gum up jets and prevent the proper mixture of fuel and air from entering the cylinder can lead to all kinds of problems over time. Here are the basics of cleaning a motorcycle’s carburetor.
NOTE: The tools needed to remove and disassemble a carburetor vary based on your motorcycle’s model, but having these two items handy will help you get the job done:
Motorcycle Carb Cleaning Basics
Step 1. Drain and remove the carburetor.
NOTE: Every carb is different in terms of the specifics of how to do this step, so consult your unit’s service manual. Find your machine’s carburetor parts diagrams here on Partzilla.com for additional reference.
Step 2. Put on goggles and gloves, then use carb cleaner and a brush to clean the outside of the carburetor.
Step 3. Open the carburetor, which can usually be done with just a Phillips or flatblade screwdriver.
PRO TIP: The screws can sometimes be a little bit stubborn. Use a handheld impact driver to help you jar the screws loose if needed.
Step 4. Check inside the float bowl for residue, and for the O-ring or gasket that seals the float bowl to the rest of the carburetor. If it has an O-ring, remove it, since carb cleaner can damage the rubber and force you to replace it.
Step 5. Remove the float bowl, which will be held in by some type of hinge pin.
Step 6. Lift off the float bowl and the float needle, and replace the needle if it’s damaged at the tip.
Step 7. Remove the jets, which typically come off with just a screwdriver. You’ll be removing the main jet, an emulsion tube, and a pilot jet.
Step 9. Inspect the jets by holding them up to see if light passes through them. If it doesn’t, you’ve got a significant clog and they need to be cleaned. Carb cleaner spray typically has a little straw so you can fire the liquid straight into the jets. Keep firing it through until you get a steady stream out the other side.
PRO TIP: Never cram a wire or drill bit into the jet to unclog it. Soaking the jet in the solvent for a few minutes might break up the clog, or try a bristle off a hairbrush as a last resort to push it loose. The jets are made of brass, which is soft, so use something softer than the brass to try and dislodge the clog.
Step 10. Use compressed air to blow through the passages on the carburetor to make sure they’re clear.
Step 11. Clean out the air-fuel mixture screw. It’s important to get it back in the same position it was when you took it apart, so screw it all the way down first, counting how many turns it took the screwdriver until it was lightly seated. Unscrew it to remove it, and however many full turns it takes to get it screwed back down, screw it all the way out and back down again with as many turns when you reinstall it.
NOTE: When you pull the mixture screw out, there’s going to be a spring, a washer and an O-ring, but you only need to clean the screw and get it back in place.
When you’re done, simply reassemble the carburetor and get it back on the machine.
If the carb is too far gone to clean it, rebuild or replace the entire assembly. Most manufacturers make carb rebuild kits that include the guts for inside the carb to get it working right again if you’re rebuilding it. Watch the video above to find out whether you should clean, rebuild or replace a carburetor.
