CDI question

[loxley007]

Hi all, I’m doing a full rewire of my 1979 CB750 and I have a question about the CDI unit.

Firstly, I only seem to have one CDI unit (see photo). Does this seem right? I understood there are supposed to be two (that’s what the wiring diagram looks like).

Secondly, if there is only one then in terms of wiring I’m not sure what the white wire goes to. The wiring diagram says ‘pick up’. Can anyone indicate what this is? For the other wires, I can see that green is ground, white/black, blue and yellow all go to the coils.

Any help would be appreciated.

Andrew

 

[Hisvett]

Hi all, I’m doing a full rewire of my 1979 CB750 and I have a question about the CDI unit.

Firstly, I only seem to have one CDI unit (see photo). Does this seem right? I understood there are supposed to be two (that’s what the wiring diagram looks like).

Secondly, if there is only one then in terms of wiring I’m not sure what the white wire goes to. The wiring diagram says ‘pick up’. Can anyone indicate what this is? For the other wires, I can see that green is ground, white/black, blue and yellow all go to the coils.

Any help would be appreciated.

Andrew

"The wiring diagram says ‘pick up’. Can anyone indicate what this is"? This normally refers to the electronic points or what would be Points in older bikes. Check out the area of the crank (probably right side) for a magnettic rotating switch mounted on the crank shaft. Good luck.

 

[loxley007]

"The wiring diagram says ‘pick up’. Can anyone indicate what this is"? This normally refers to the electronic points or what would be Points in older bikes. Check out the area of the crank (probably right side) for a magnettic rotating switch mounted on the crank shaft. Good luck.

Cheers, I’ll give that a look tomorrow.

Big question though…should there be one CDI or two units?

 

[Hisvett]

Looking at a 1980 DOHC Wiring drawing, I see two ignition coils and two spark units (CDI). I'm assuming your '79 is setup the same.

 

[mrtwowheel]

You need two spark units. The pickups are inside the left front engine cover, timing is changed by moving the pickups.

 

[loxley007]

Cheers all.