Bing 54 carburetor service - shop supplies, tools and service procedure.
Bing 54 Carburetor Service Procedure.
If you have an engine with dual carbs - it is suggested you do one carb at a time, so that you can use the other for reference if needed or you can refer to the parts guide.
Remove the cover plate (9) and piston assembly (3) from the carb body. To separate the piston assembly from the cable, grasp the cover plate in the palm of your left hand, grab the spring with your extended fingers and compress the spring. Now with the spring compressed, used the needle to push the spring cup up, push down on the throttle cable until it is free of the piston, move it sideways and it will come free of the piston, release pressure and the unit will come apart.
Note the clip (5) and needle (4) are located BELOW the Spring cup (6).
Inspect the rubber grommet (13) for signs of cracking, A cracked grommet will allow water to run down the cable into the float bowl.
Inspect the piston for wear in the area where the idle adjustment screw rides.
Inspect your needle and clip for wear - check if you have the updated clip, spring cup and rubber washer.
Inspect the rubber sealing ring (8) for damage.
If you have an older carb check to see if the cable has been wearing on the adjuster screw (12).
On older carbs the cover plate (9) could be put on incorrectly - with the hole offset, which would damage the throttle cable.
New carbs have pins so that the cover can only be installed one way.
Unscrew the Idle Air Mix Screw and remove the O ring around the head of the screw.
Next remove the Idle Adjusting screw and spring. Inspect the screw for wear.
On newer carbs remove the single vent tube, on older carbs remove the two vent tubes.
To remove the float bowl pry back on the Spring Clip (26) and pry down on the bowl.
In some cases where the engine has been improperly stored, corrosion will have formed in the bowl and it may be necessary to gently tap the bowl with a plastic hammer.
Remove the float bowl gasket (24).
Remove the two floats (21).
Remove the Sieve Sleeve (18) from around the main jet post.
Unscrew the Main Jet from the Mixing Tube, Unscrew the Mixing Tube. Remove the Needle Jet. Located just beside the main jet is a cavity where the Idle Jet is located unscrew it (this requires the use of a small screw driver).
Too large of a screw driver will DAMAGE the jet! The screw driver in the Rotax tool kit is ideal for this.
In order to remove the Needle Valve (19), Needle Clip (20), and Float Bracket (22) we first need to remove the Float Arm, we must remove the Hinge Pin that holds the Float Bracket in place.
The Hinge Pin is smooth at one end, and knurled at the other. The knurled end holds the pin in place. Using a hammer and small drift, drive the pin out from the non knurled end of the pin. A light tap on the opposite end should dislodge the knurled end of the pin, and free it. Once free, slide it out of the carb. With the pin removed, remove the brass Float Bracket (22), and then the spring clip and Float Needle (19/20).