Checking the Fuel Metering Distributor

Fig. 15 Fuel Mixture Regulator:

NOTE: The piston (2),Fig. 15 and its sleeve (3),Fig. 15, of the fuel metering distributor, are matched. When handling these parts it is advisable to avoid all impacts.
1. Remove the piston (2)Fig. 15.
2. Check for gum deposits and signs of seizing. If gum deposits are found on the piston clean it with clean gasoline.
3. Ensure that it does not bind inside its sleeve by sliding it back and forth while turning it.
4. If a high spot is found, replace the metering distributor.
5. Install a new "O" ring (4)Fig. 15.
6. Reinstall the metering distributor.