How to set the ignition timing on the Honda CB500K / CB550 – CMC Help Center

It can be difficult to stress just how important learning to set your ignition timing is on a vintage Honda motorcycle. One of the biggest causes of troubleshooting headaches we see all stem from the ignition system and timing. If you do not know without a doubt that your ignition timing is perfect, then you will never be able to truly troubleshoot and ignition system issues. Setting your ignition timing has to be done every 1,500 m (2,400 km) and is what we consider the "weed-out" skill in keeping your motorcycle reliable and performing properly. If you do not know, this is also the final step in your standard tune-up procedure so be sure to have already changed your oil and adjusted your cam chain and valves.

Before getting started, if you never have rebuilt and regreased the ignition advance be sure to do that now. We have a video of how to do that and why it is so important right here:

How To Service The Mechanical Ignition Advance Mechanism On Your Vintage Honda Motorcycle

Points Gap

To set the left points gap you need to turn the engine to about 90 degrees past the fire mark for cylinders 1 and 4. The viewing window will show a small tang on the ignition advance and this indicates the highest point on the ignition cam is contacting the left point.

Point gap: 0.012" - 0.016" (.305mm - .406mm) Service Limit: 0.024"( .610mm)

Always set the point gap as small as possible.

Loosen the point on the points plate and insert the feeler gauge in between the contact pads. With the feeler gauge in, tighten the points screws to lock the point in the position where you can just feel a small amount of drag on the feeler gauge when moving it back and forth in between the pads. Repeat the process for the right point with the engine about 90 degrees past the fire mark for cylinders 2 and 3. Be sure to watch the video above for the complete instructions.

Ignition Timing (Static)

Static timing is set using a timing light according to the process laid out in the Honda Service manual. It involves connecting the test light to the positive connection of each point and ground of the engine to see the exact moment when the point pads make contact. You will then adjust the points to allow for them to contact the moment the engine hits the F mark for cylinders 1&4 (left point) and 2&3 (right point). Be sure to watch the video above for the complete instructions.

Warning:

Always turn your kill switch off when not actively checking the timing. This cuts power to the coils to keep them from cooking/melting during the timing process.

The left point will be adjusted by moving the main points plate and the right point will be adjusted by moving the right point subplate. If you loosen the point itself, it will compromise the point gap you set earlier.

Dynamic Timing

Dynamic timing is set using a stroboscopic timing light with the motorcycle warmed up to operating temperature and at idle speed. The stroboscopic timing light allows you to see the timing in action live while the motorcycle is running and you can make the final adjustments to the timing plate to get your timing dead on. Be sure to watch the video above for the complete instructions. You can take your timing one step further by checking the timing of your full advance but we do not cover this in our instructional video because we have found that these 3 methods get you 99% of the way there. If you would like to learn how to set your timing at full advance with the stroboscopic timing light, refer to the Honda service manuals timing section for the CB500K and CB550.