Suzuki DF 25 Service Manual page 41

2-14 PERIODIC MAINTENANCE
Turn balancer air screw A to left/right to bring the steel ball
to the center line of the tube.
6. Connect each hose of No.1 tube and No.2 tube in synchro-
nizer to the adapter 2 in turn.
Turn each balancer air screw B . C to bring the steel ball
to the center line of each tube.
[ Synchronizing throttle valves ]
7. Remove the remaining impulse plugs from No.1 & No.2 in-
take manifold, then install carburetor synchronizer gauge
adapters.
8. Connect each synchronizer hose to corresponding intake
manifold adapter by marked number.
9. Start the engine.
NOTE:
When synchronizing the throttle valves, it is very important to
synchronize them in the idle position rather than any other
throttle position.
10. With the engine warmed up and idling at specified speed,
the steel balls must be at the same height in each of the
tubes.