Ignition Timing

Engine must be at normal operating temperature. Connect tachometer and timing light to engine. Connect tachometer lead to negative terminal of coil.
Check timing with choke valve fully open, transmission in Neutral, all vacuum hoses connected, and accessories turned off. Adjust idle speed to specifications.
On Federal low altitude models, flywheel timing mark should move when vacuum hose between HAC valve and distributor sub-diaphragm is pinched near valve. On high altitude models, timing mark should move when sub-diaphragm hose is reconnected.
On models with dual diaphragm distributors, disconnect and plug vacuum hoses at both main and sub-diaphragms. Adjust timing by turning distributor. Reconnect hoses to distributor diaphragm(s).

Fig 1: Ignition Timing Marks

IGNITION TIMING (DEGREES BTDC @ RPM)

Application	Setting
Land Cruiser	7 @ 950