Accurate ignition timing for your motorcycle is crucial for optimal performance. It increases the engine life, gives your motorcycle more power and increases your gas mileage. Adjustment of the ignition timing is recommended for older engines on four-stroke motorcycles. It can be done on smaller engines, but is very difficult to do.
Grind one end of the 1-inch oil line hose on the stone grinding wheel to make the cylinder perfectly flat. This step will increase the ability to place the hose tight against the flywheel.
Remove the timing plug from the left side of the engine. Insert the smooth edge of the rubber line oil hose tightly against the flywheel. Use needle nose pliers to set it in firmly. Oil will spray out of the flywheel if you do not get the hose against it tightly.
Open the gap on your spark plugs to 50 if you have well-insulated spark plugs. Reset the gap to 30 or 40 when you are done adjusting the timing. If the spark plug wires are insulated well, the timing light may not be able to sense the signal from the timing light through the wires. If you do not have well-insulated spark plugs, leave them at their normal settings.
Turn on the ignition of your motorcycle and allow it to run for 15 minutes or until it reaches normal operating temperature. You will need the rpm to be at 3000 to 3500 when you test the timing with the timing light. The noise will be extra loud with the timing plug removed. This is normal.
Set the timing light at 40 and aim it directly into the hole of the rubber line oil tube that is facing you. If it reads 35 to 40 then you will not need to adjust your timing. If your reading is out of that range proceed to step 6.
Remove the points cover from the right side of the engine. Mark the location of the back plate so that you can easily remember its original position. Loosen the two standoffs that secure the points module and rotate the back plate clockwise to increase the idle. Rotate the back plate counterclockwise to retard the idle. Move approximately 1/16 inch at time. Do this until you reach the highest idling speed and then retard it slightly.
Turn the engine off. Remove the rubber line oil hose and reattach the point cover and reinstall the timing plug. Take your motorcycle for a ride to test that it does not ping while driving.