How to Remove a Carburetor From Vehiclesby Contributing WriterUpdated June 12, 2017
Performing maintenance on a Vehicles that has been stored Vehicles a few months begins with removing the carburetor. Dust and debris can collect in the ports of the carburetor and cause the engine to bog down and smoke. The most important thing to remember when removing the carburetor from a Vehicles is the reassembly process. Vehicles have a notoriously small working area and the carburetor is located in the middle of various cable paths; labeling these cables or taking pictures of the disassembly process will help when you put the bike back together.
Under The Hood:
- How to Remove a Carburetor From a Yamaha Motorcycle
- How to Remove the Carburetor From a Honda CB750
- How to Remove the Carburetor From a V-Star 650
Detach the battery cables and remove the battery from your Yamaha motorcycle. This is a safety precaution since you will be working in a small space around fuel, where a spark from a dropped tool can cause a fire.
Remove the bolts from the seats and tank depending on the make and model of your Yamaha. The carburetor will be located at the top of the jugs directly under the seat or fuel tank.
Turn the fuel valve to the "off" position. Residual fuel from the carburetor will come out but this prevents fuel inside the tank from leaking out onto the work surface. Remove the butterfly clamp from the fuel hose and drain the trapped fuel into a gasoline safe container.
Remove the Allen bolts holding the speedometer cluster in place. Pull the speedometer cluster wires from their clips underneath the speedometer. Remove the intake hose and other air lines from the fuel tank. Remove the hoses from the gas tank to the carburetor. Lift the tank and seat off the top of the bike and set it aside.
Relocate the sensor and air lines that run across the top of the carburetor. Move the lines to the side if they are long enough. If the lines are too short to relocate, label them and remove the obstructing end. Be careful when removing hoses or relocating them. Crimped wire connections, fuel lines or air lines can cause a malfunction.
Remove the throttle cables. Loosen all four Allen bolts in the carburetor plate. Wiggle the carburetor to break the seal on the gasket before you lift it up. Remove the overflow tubes from the bottom of the carburetor. Lift the carburetor free from the frame and pass it between the jugs on the right hand side of the bike.
Items you will need
Phillips and slotted screwdrivers
Gasoline safe container
Needle nose pliers
Masking tape (optional)
Permanent marker (optional)
Lift your CB750 onto its center stand. Unlatch the seat, using the seat lock built into the motorcycle's frame. Lift the seat into its fully-opened position, by hand. Pull the frame covers off both sides of the motorcycle, located below the seat rails, by hand.
Disconnect the negative cable from the battery, located between the seat rails, using a Phillips screwdriver.
Remove the mounting bolt from the base of the fuel tank, using a socket wrench and a 12 mm socket. Older CB750 models do not use a mounting bolt, relying instead on a tab that is inserted into the rubber grommet at the base of the tank. Pull the tab out of the grommet, by hand.
Turn the fuel valve lever, located under the left side of the fuel tank, to the "Off" position. Lift the base of the fuel tank up slightly, then pull the fuel hoses off the fuel valve outlet with pliers. Pull the fuel tank away from the handlebars, then set the tank aside.
Unbolt the voltage regulator from the left side of the engine, using a socket wrench and a 10 mm socket. Unplug the regulator from the wiring harness, then pull it away from the engine. This step applies only to 1984 or newer CB750SC Nighthawk models.
Loosen the air box mounting bolts, located above the air box near the seat rails, using a socket wrench and a 10 mm socket. Loosen the clamps attaching the air box ducts to the carburetor inlets and the engine intake flanges to the carburetor outlets, using a Phillips screwdriver.
Push the air box away from the carburetors by hand to separate the air box ducts from the carburetor inlets. Pull the carburetors off the engine intake flanges, by hand. Pull the carburetors out from the left side of the motorcycle.
Unscrew the choke cable retaining screw, using a Phillips screwdriver. Pull the choke cable out of the carburetor choke lever.
Remove the throttle cables' barrel-shaped ferrule from the throttle valve catches at the center of the carburetor. Unscrew the carburetors' top caps by hand, then pull the throttle cables out from the throttle slides, by hand, if you are working on an 1976 or older CB750 model.
Loosen the float chamber drain screws on the bottom of the carburetors, using a flat screwdriver. Drain the fuel remaining the in the float chambers into a gas can, using a funnel. Tighten the drain screws after the float chambers have drained completely.
Items you will need
10 and 12 mm sockets
Disconnect the battery cables from the battery under the seat. Turn the fuel petcock or valve -- located next to the carburetor on the right side of the engine -- to the "Off" position.
Locate the fuel hose connected behind the fuel petcock. Using a pair of long-nose pliers, slip off the clamp towards the middle part of the hose. With a twisting motion and the fuel container on hand, remove the fuel hose and drain the fuel into the fuel container.
Locate the bolts under and on top of the fuel tank and unscrew them all. On the V-Star 650, the speedometer sits atop the fuel tank assembly so you should unplug the electrical connections and speedometer cable before you can remove the speedometer gauge. You will see a vent hose leading from the fuel tank to the intake manifold. A small clamp holds this hose in place. Remove this hose from the fuel tank. You can now remove the fuel tank, which will reveal the airbox and ducting on the right side of the airbox.
Loosen the clamps that hold the airbox onto the carburetors. There will be two clamps that you have to loosen. These fit onto the carburetor intakes. You do not need to remove the clamp screws entirely. Remove the airbox and the ducting to expose the carburetor assembly.
Locate the Allen bolts under the carburetors and in the "V" of the engine. Loosen and remove the bolts. There are a total of 4 bolts in all, 2 on the left and 2 on the right.
Wiggle the carburetor to break the adhesion of the gasket to the carburetor. You should double check the carburetor connections to see if you missed removing any hoses or connections.
Loosen the adjuster on the throttle cable at the handlebar. Locate the carburetor linkage and remove the throttle cable connection from the linkage. You can now remove the entire carburetor assembly through the right part of the bike.
Items you will need
Set of Allen wrenches
Long nose pliers
Digital camera or masking tape and marker