Servo Diaphragm
1. Connect a suitable tachometer to the engine.
2. Operate engine and ensure engine idles properly. Switch engine off and remove air cleaner.
3. Disconnect vacuum hose from servo diaphragm. Connect a suitable vacuum hose between intake manifold and servo diaphragm. Start engine and increase engine speed to 2000 RPM with throttle lever, then release throttle lever and ensure engine speed is 1100 to 1300 RPM, adjusting as necessary.