Servicing diaphragm carburetors

As a very general rule of thumb, most metering levers are adjusted to stand flat or just below the surrounding metal. Zama, for example, calls for the metering needle to be 0 – 0.3 mm (0 – 0.012 in.) below the carburetor body. A depth gauge can be used in the absence of the proper [...]

There are times when one must remove Welch and expansion cups for access to internal circuits, but do not rush into the job. Figure 4-29 shows correct and incorrect ways to attack a Welch plug. The chisel goes in at a shallow angle to avoid scarring the carburetor body. Note the depth of the plug [...]

Once you made a thorough diagnosis, repairs are anticlimatic. But do not expect miracles. Nothing can be done for carburetors like the one in Fig. 4-27. The next priority is to obtain a repair kit. Some engine makers refuse to catalog these kits, preferring to sell new carburetors instead. But carburetors are off-the-shelf items, used [...]