General information
1. Since no provision exists for adjusting the
ignition timing and since no component is subject to mechanical wear, there is no need for regular checks; only if investigating a fault such as a loss of power or a misfire, should the ignition timing be checked.
2. The ignition timing is checked dynamically (engine running) using a stroboscopic lamp. The inexpensive neon lamps should be adequate in theory, but in practice may produce a pulse of such low intensity that the timing mark remains indistinct. If possible, one of the more precise xenon tube lamps should be used, powered by an external source of the appropriate voltage.
Note: Do not use the machine's own battery as an incorrect reading may result from stray impulses within the machine's electrical system.
Check
3. Warm the engine up to normal operating temperature then stop it.
4. If the belly pan on your model obscures the alternator cover, remove it (see Chapter 8). Unscrew the timing mark inspection cap from the alternator cover (see illustration). Check the condition of the cap О-ring and discard it if it is damaged, deformed or deteriorated.
6.4. Unscrew the timing inspection cap (arrowed)
5. The timing mark on the rotor is an 'F' which indicates the firing point at idle speed (note that each cylinder has its own 'F' mark, that for the front cylinder being adjacent to the 'FT' mark, that for the rear cylinder being adjacent to the 'RT' mark) (see illustration). The static timing mark with which this should align is a notch in the top of the inspection hole.
6.5. 'F' mark and static timing mark
The rotor timing mark can be highlighted with white paint to make it more visible under the stroboscope light.
6. Connect the timing light to the relevant HT lead as described in the manufacturer's instructions.
7. Start the engine and aim the light at the static timing mark.
8. With the machine idling at the specified speed, the timing mark should align with the static timing mark ('F' or 'R').
9. Slowly increase the engine speed whilst observing the timing mark. The timing mark should move anti-clockwise, increasing In relation to the engine speed until it reaches the full advance mark (no identification letter).
10. As already stated, there is no means of adjustment of the ignition timing on these machines. If the ignition timing is Incorrect, or suspected of being incorrect, one of the ignition system components is at fault, and the system must be tested as described in the preceding Sections of this Chapter.
11. Install the timing inspection cap using a new О-ring if necessary, and smear the O-ring with clean oil. Apply a smear of molybdenum disulphide grease to the threads of the cap and tighten it securely.