Vintage Motorcycle Old Dyna Ignition Coils on My 750 Honda, CB750 Ignition Coil Replacement

Vintage Motorcycle Rescue 750, Old Dyna Coils being replaced by new OEM Type coils that were bought on ebay. The problem is that when I rebuilt the motor and attempted to start it, all that it did was to pop and backfire, it sure was loud.
My first thought, since it was five years ago that I stopped riding and the bike was running fine at that time, and that I recently totally repainted the frame, that I had somehow lost the grounds on the electrical system. I never thought that it was the ignition coils that went bad by just sitting.
So, I removed the engine mounts and ground all of the mounts contact area to bare metal. Then I ground the contact area on the engine and on the frame also. I then cleaned every connector on the wiring harness and cleaned the Dyna III Ignition pickup plate back where it touches the engine ground. None of that seemed to make any difference at all.
So, I replaced the coils and that made a big difference. The engine started easily and ran great. The Dyna coils went bad and needed to be replaced.

[@TicoM0la]

hi guys.. i believe i have the same issue on my cb 750 76' .. In my case the bike struggles to keep the idle unless I rev it up quite a lot..

[@vintagemotorcyclerescue7506]

That was a problem with mine too and also it had flat spots in the acceleration. The coils fixed a lot of problems.

[@allseeingguy5485]

You could also have charging system issues. Check your stator and regulator. There are many videos on how to test them with a multimeter.

[@TicoM0la]

Thanks guys!
I changed the ignition system, installed a dyna S system and it runs like a charm !!