ADJUSTING IGNITION TIMING
Requirements for exact ignition timing adjustments:
a) Engine at operating temperature (oil temperature
at least 60°C / 140°F).
b) Points in perfect condition.
c) Dwell angle correct.
d) TDC position sensor mounted correctly.
Connect BMW service test unit or BMW digital
tester according to operating instructions.

73034121 - click to zoom
 
1) Dwell Angle
Version with Breakerless Transistor Ignition:
The dwell angle is given by design and can´t be
changed.
Check dwell angle¹).
Important: Stop engine and turn off ignition
prior to performing any work on a breakerless
transistor ignition system. DANGER!


Siehe auch ¹) See microfilmed Specifications
 
Version with Contact Breaker Points:
Remove distributor cap, rotor and dust cap.
Start engine.
Adjust dwell angle¹) by turning the point carrier.
The smallest value would be ideal.


Siehe auch ¹) See microfilmed Specifications
63012071 - click to zoom
 
2) Ignition Timing
A) BMW 630 i:
Pull off vacuum hose (S).
Start engine.
Check ignition timing¹).
Correct by loosening distributor mounting screw
and turning the distributor to adjust the ignition
timing.


Siehe auch ¹) See microfilmed Specifications
63012073 - click to zoom
 
B) BMW 633 i:
Pull off vacuum hoses for advance (1) and retard (2).
California Version and 49 State High Altitude
Version models with an automatic transmission
will only have retard hose (2).
The connection on vacuum box is plugged.
Start engine.
Check ignition timing¹).
Correct by loosening distributor mounting screw
and turning the distributor to adjust the ignition
timing.


Siehe auch ¹) See microfilmed Specifications
73312030 - click to zoom