Questions and Answers

Honda CB 400 Dual Ignition Points Q. I have a 1975 Honda CB 400 four. It has two sets of points, one set fires fine the other not at all. I have power going to the points but when I turn it over the coil does not fire. When I close and open the points with metal probe I get fire from my spark plugs! why won't it fire through the points when I turn the engine? Thank you for your help, Dave

A. How do you have them wired? You need to have the wire from the negative side of the coil go to both sets of ignition points. If one set of points are closed, opening and closing the other set won't produce a spark. One has to be open and the other closed to create a spark by opening one set of points.

The two sets of points are positioned in the distributor so that their open and closing timing is slightly overlapped. One set becomes the closing (or make) and the other set becomes the open (or break) set. This timing overlap provides the ability to set a longer dwell time that applies voltage to the coil for a longer duration of time. The longer dwell time provides about 20% hotter spark than with a single point setup.

To set them, disconnect one set and set the dwell one the first, or primary, ignition points. The dwell should be 50°F. Once the primary ignition points are set, move the primary wire to the secondary ignition points and set the dwell to 50°F. Then hook up both sets of ignition points and you're set.