1980 HONDA CB400N SUPER DREAM

Q:

Some time ago I purchased a 1980 Honda 400N Super Dream; she was a smart-looking example and ran nicely with no rattles. The day after I got it home I tried to fire her up, but she would not start. I removed the left-hand plug to check for a spark, and when I tried to start it she fired up on the right-hand cylinder. Upon replacing the plug she started and ran on both cylinders. I left her ticking over for a few minutes, switched her off, went to re-start her, but she would not start. I removed the plug and again she started. Have you any idea what is going on? I have replaced the coil, leads, plug caps and plugs with no change.

Phil Budding

A:

That is very interesting, not to say mysterious, but the CB250N and CB400N do suffer from ignition faults, despite being fully electronic. You could see if you can get second-hand Honda components and test by substitution, but one company which can offer some help is Rex’s Speed Shop, who you can contact on 01580 880768. If you have access to a computer, they have produced a specific self-help sheet at: https://www.rexsspeedshop.com/wp-content uploads/2018/ 10/REXS-CB250400N-CB250400Tgenerator-testing-guide.pdf which describes how you can test the various components of the ignition system to see where the fault might lie. They also produce a replacement CDI unit for £83, which they claim is an improved version of the Honda unit, which is a pretty good price for this type of product.