How to Rebuild a Keihin Carburetorby Lina Schofield
Keihin carburetors are used on motorcycles and all-terrain vehicles.You might decide to rebuild a Keihin carburetor if you are re-jetting it or if you are performing a tuneup, especially on older vehicles. If you have an all-terrain vehicle, you should rebuild the carburetors after riding in muddy or dusty locations. Carburetors should also be rebuilt on all -terrain vehicles or motorcycles that have been sitting in storage with fuel left in the carburetor assembly to prevent future performance issues. Do not take the carburetors off the rails to keep them in sync as you perform these steps.
Remove the carburetor from your motorcycle or ATV. This procedure will vary from vehicle to vehicle. Consult the repair manual for your vehicle if you are unfamiliar with the procedure for removing the carburetor.
Turn the carburetor over to access the four retainer screws securing the float bowl onto the base of the carburetor assembly. Lift the float bowl away from the carburetor.
Slide the horizontal retainer pin out from the top of the floats and pull the floats out of the carburetor. Unscrew the pilot jet and the main jet by twisting them counterclockwise manually.
Measure and cut one foot of copper wire. Repeat two more times.
Coil two pieces of the wire around each other and push them through the larger jet holes repeatedly to scrape out any fuel buildup or dirt that is trapped in the holes.
Bend and kink the third wire. Push the wire through the smaller jet holes to remove residual fuel and dirt.
Direct the carburetor cleaning spray into every single jet hole and coat the jet holes thoroughly with the spray.
Twist the jets into the base of the carburetor assembly. Bend the metal tab on the fuel needle to position the float height directly underneath the fuel needle.Screw the float bowl back in place.
Repeat the previous steps on your remaining Keihin carburetor.