no spark on a 78' CB750 Rebuild

[vandernf]

Hey everyone,

I have been having trouble getting spark on wiring a 750 from scratch. The bike ran perfect before I took it apart.

So far I have just wired up the starter motor to a switch to check for spark on the turn over...and there is none.

This is what I have hooked up (cb owners will know what I am talking about)

The BLUE and YELLOW wire are connected from the points to the ignition, the starter turns over fine. I do not have the regulator or rectifier wired up yet.

Any ideas why I am not getting anything? Correct me if Im wrong, but should the bike spark even if the regulator and rectifier ARENT hooked up because these components are only used in the power generation from the alternator?

Any input is appreciated! Thanks everyone

 

[vandernf]

I also want to add that I have new plugs.

I just want to clarify that I am just trying to verify spark on the initial turnover when the starter in engaged. Once I confirm there is spark, I will continue to wire up the rest of bike from there.

Thanks

 

[TheJester]

Just double check your basics, I have been fooled a few times by stupid stuff like a kill switch, or grounded wire somewhere.

 

[Rich Ard]

It sounds like you have not run power to the coils, right? It'll need that to spark.

 

[jungalist]

It sounds like you have not run power to the coils, right? It'll need that to spark.

+1
you only wired up the breakerpoints which just make contact with the mass, they don't run any power.
wire up your rectifier. then it'll work i guess, right?

 

[vandernf]

OK it makes sense to power the coils...but if you look at this wiring diagram, can someone explain how it is done?

Here is the wiring diagram for the bike:

http://manuals.sohc4.net/CB750K/CB750_K8_WD.jpg

 

[TheJester]

put power to your black/white wire. the yellow and blue wires are switched to ground by the points