CB750 K2 1973 actually! So, bike is a little down on compression, especially cyl 2 - has been stood 12 years. Many faults found on ignition Primary circuit. Decided to upgrade - all on videos...

Dyna electronic ignition - full install & setting ignition timing

By Andy Mechanic on 22 January 2021

One of the upgrades in this 1972 Classic Honda was to sort the ignition system. When the bike came into the workshop it was very difficult to start & when running wasn't smooth, often misfiring & under powered. Initial inspections found may faults with the Primary ignition circuit, excessive voltage drops in the wiring, connectors, ignition switch & even the kill switch! In previous Episodes these issues were all fixed & now it's time for the icing on the cake - Electronic Ignition!

Parts Worked On:

Electrical System

How to fit new ignition points & set ignition timing - no special tools required!

By Andy Mechanic on 22 January 2021

Now I know we will be fitting a Dyna electronic ignition system to this bike but whilst it's still got the original contact breaker setup now is a perfect time to run through the correct procedure to replace the ignition points, condensers & how to re-adjust the ignition timing so it's spot on. The art of installing 'points' is a dying art for sure, many have never seen such an odd electro-mechanical concoction let alone know how to service it! So, I felt it a great idea to get this info up on the 'Tube' before even I forget how to do it!

Parts Worked On:

Electrical System

Making up new HT leads for the CB750

By Andy Mechanic on 22 January 2021

During the inspections on the ignition system on this Classic Honda 4 cylinder motorcycle we found so many issues, including, but by no means limited to, open circuit plug caps, damaged HT leads, suspect coils & way more faults within the wiring loom to mention so the owner 'bit the bullet' & Dyna ignition coils were fitted. These coils, unlike the Genuine Honda ones, do not have integral HT leads, bonded into the coil's casing, instead they are like those used with distributor type ignition systems found on older cars.

Parts Worked On:

Electrical System

Dyna 3 ohm ignition coils - full install

By Andy Mechanic on 22 January 2021

With the bike's loom modified & ignition relay fitted in the last video we can now get around to installing the new Dyna (high power) ignition coils. This video covers the step by step process & includes a few helpful mods/tips that will maximise the benefits of fitting these expensive upgrade coils... In the next video in this Series we will be then able to make up new ignition HT leads using the kit I ordered from the UK. Enjoy Andy

Parts Worked On:

Electrical System

Ignition Primary circuit upgrade - fitting an ignition relay

By Andy Mechanic on 22 January 2021

On the old Japanese motorcycles the current for the ignition system (coils) runs through both the main ignition switch (key) & also the kill switch - not ideal & will, over time, cause damage to the internal contacts to to arcing etc. So, as part of the ignition system upgrade on this old Honda CB750 we are going to make a number upgrades, & the fitting of an ignition system relay is just one of them....

Parts Worked On:

Electrical System

Inspecting the Primary ignition circuit

By Andy Mechanic on 22 January 2021

With the new parts for the front brake caliper on order we can now crack on with the repairs to the ignition system - remember that weak spark we discovered during the initial check over of the bike? Well, now I finally have the time to dig a little deeper to find out the true state of the wiring on this bike. Using the basic 'Volt drop' test we can quickly identify points of high resistance along the wiring that makes up the Ignition system circuit.... The method used in this video can pretty much be applied to any electrical circuit & is a very useful way of identifying problems.