CDI / Spark Box Wiring (Motogadget Components) ?

[jeremieC]

So, the bike I'm working on is a 1981 Honda CB750 Custom.
(attached file is the M-Unit and CDI Diagram from Revival Cycles) - the Spark Boxes / CDI Boxes doesnt really appear to be the style Im using

I'm using a Motogadget M-Unit Blue, I've upgraded my Reg/Rec and using an Antigrav battery. I've started the wiring process but I'm not sure how to handle the Spark Boxes (CDI Boxes) / these seem to be called different things depending on who you talk to you.

The best thing in the world would be a picture, a real picture of how the spark Boxes are wired into the system of a bike with similar components, otherwise if someone could perhaps explain it like I'm 5. I'm normally pretty confident but with the wiring I feel like I'm riding the short bus and sniffing glue lol.

 

[teazer]

OK. that bike doesn't have a CDI, it has TCI which is transistor controlled ignition and they are usually called Ignitor units. But that's not really important. What that diagram shows is how to connect the M unit through a relay so that the M unit switches a small amount of power to the relay and the relay handles (switches) the CDI to ground to kill the system.

Your system carries 12v from the switches to the Ignitors, so you need to get the correct wiring diagram and then check your wiring diagram for that bike and follow it. The only thing that you really change is how power gets routed to different parts of the bike. For the ignition, locate the wire that used to carry switched 12v from the run/kill switch to the ignitors. In it's place you will run the new wire from the relay.

 

[jeremieC]

OK. that bike doesn't have a CDI, it has TCI which is transistor controlled ignition and they are usually called Ignitor units. But that's not really important. What that diagram shows is how to connect the M unit through a relay so that the M unit switches a small amount of power to the relay and the relay handles (switches) the CDI to ground to kill the system.

Your system carries 123v from the switches to the Ignitors, so you need to get the correct wiring diagram and then check your wiring diagram for that bike and follow it. The only thing that you really change is how power gets routed to different parts of the bike. For the ignition, locate the wire that used to carry switched 12v from the run/kill switch to the ignitors. In it's place you will run the new wire from the relay.

thank you!

so, during the rebuild process, I pulled all the wiring, the old harness is long gone so I'm rewiring all over brand new everything.

If I'm understanding your reply I'll need a relay that distributes smaller amounts of power through it to the switches?

 

[teazer]

Not exactly. I was explaining your ignitors relative to that diagram for a CDI ignition system. The M-Unit should have a wiring diagram and instructions on how to connect everything. The question has been asked before. Please search for answers.

Revivial on their web site says that all you need to do is to identify the switched 12v to your Ignitors and connect it to the appropriate Ignition out connection on the M Unit Blue. They even go on to explain that Honda called ignitors CDI units when they were actually TCI designs and that is a big difference for wiring.