Engine Fires on One Cylinder. Is my Condenser Bad?

If you bike is hitting a wall at about 5000 RPM and bogs hard, you may have a bad ignition condenser. Here is a quick test to see if there is a bad condenser is on your vintage Honda CB or CL Scrambler.

 

The twins with dual ignition coils  (CB350, CB360, CB450) will typically drop a single cylinder. Similar goes for the 4 cylinder CB550 and CB500K bikes, you will drop cylinders 1 & 4 or 2 & 3. 

 

Run your bike with the points cover off in a dark environment and watch the points open and close. See how the left ignition point is sparking excessively but the right one is not. The left side condenser is bad. If you do see a very small spark every 2 to 3 seconds that is OK, but this large bright spark every time the points open indicates that the condenser is faulty. This video was taken on a CB550, however the same will apply for any of the vintage Honda's. The CB350, CB360 and CB450 family of bikes use a condenser that is a single unit but is actually two condensers on a common bracket. If one side is bad then the whole unit will have to be changed. On CB550 and CB750 models there is a condenser for each side.