Schebler Carburetor Adjustment


Instructions for attaching and adjusting.

Remove Indian carburetor and take out nipples on manifold and put them in schebler manifold. Attach manifold connection to manifold leading to cylinders. Remove Indian control rod and substitute control rod furnished. Remove Indian gasoline union and solder line into schebler gasoline union and adjust carburetor according to instructions below. If in attempting to start the engine for the first time, it does not run perfectly, first see that it has proper ignition, as per your instructions. If the difficulty seems to lie in the carburetor, proceed as follows:


Intermediate Adjustment. See that the leather air valve ‘A’ seats lightly, then open throttle until lift lever roller rest at ‘II’. Next open knurl button ‘I’ about three turns; turn knurl button ‘I’ to right until mixture becomes so lean that the motor backfires or misses; then turned ‘I’ to the left until motor and smoothly.


Low speed adjustment. Close throttle and open low speed are adjusting screw ‘L’ about three turns, then turn low speed cam adjusting screw ‘S-6’ to the left until mixture becomes so lean motor backfires or misses. Turn ‘S-6’ slowly to right until motor runs smoothly. If, with this low speed adjustment motor runs too fast, turn ‘L’ to the right or in.


Hi speed adjustment. The carburetor is now ready for the high speed adjustment and the throttle and spark should be advanced. The adjustment is now made by the pointer ‘Z’ which, as it moves from ‘1’ toward ‘3’, increases the supply of gasoline; moving the indicator from ‘3’  toward ‘1’, cuts down the flow gasoline. When the indicator reaches the right point, the engine will run without missing or backfiring. If, when lever ‘Z’ is turned to figure ‘3’, mixture is still too lean, causing motor to backfire, increase tension of air valve spring by turning air valve adjusting screw ‘12’ to the left. The high speed air valve on the side of the carburetor is to be used only for extreme high speed. This valve should be kept closed when adjusting the carburetor.


Starting. The air valve can be locked in a closed position, which materially helps easy starting. It operates as follows: Pull out knurl button ‘12’, give one quarter turn. When motor is started, turn button ‘12’ back. This release is air valve ’A’ and allows it to operate in the customary manner. The Locking feature of the air valve does not in any way alter the instructions for adjustment of the air valve. When first starting the motor if it backfires, on account of the motor being cold, do not readjust the carburetor, but wait until the motor warms up.


Remedy for flooding. Great care should be taken to see that there are no particles of dirt or foreign substance in the tank or line, as any foreign matter impedes the regular flow of gasoline, and causes the carburetor to miss, or backfire. Oftentimes particles of dirt or sediment from the gasoline will lodge under the float valve ‘H’, prevent same from seating properly, and cause flooding. In order to clean out the float valve seat: remove the bowl cap and raise float valve, allowing the carburetor to be flushed thoroughly. To clean out the bowl of the carburetor, remove the bowl by disconnecting the gasoline line and removing the bowl lock nut at the bottom.