ignition timeing issue CB750 1980

[headhunter8]

haveing a timing issue with 1980 cb750 the spark is happening 90 degreas after it passes the pulse genorator pick up( found this out with a timeing light and this is happing on both 1-4 and 2-3 anyone have any ideas when it would be doing that?

 

[Sonreir]

Yes. You have the points wires switched. Swap the blue and yellow wires on the coils.

 

[headhunter8]

thank you i wil give that a try

 

[headhunter8]

tested this and did not work still off 90

 

[headhunter8]

would bad coils or pulse generators cause this

 

[Sonreir]

Swap the plug wires, then. Swap 1 & 2 and then swap 3 & 4 and see what happens.

 

[headhunter8]

still sparking 90 degrease late

 

[Sonreir]

Hmmm... possible the pickup is installed incorrectly?

When did the issue begin?

 

[headhunter8]

just got the bike for a new build trying to get the motor to started for the first time and as far as i can tell from the manual everything is installed right and when i test the pick ups the seem to work ok i just dont want to go buy parts until im looking in the right direction

 

[Sonreir]

Pickup is on the side of the crank, right? Any way to rotate it 90°?

 

[headhunter8]

i did try that earlier the timing does move but there is no way to screw it down with our cutting the plate

 

[Sonreir]

If you're rotating the pickup and the timing isn't changing, I suspect it might be your ignition unit.

 

[headhunter8]

i wonder what would cause the delay would a bad coil slow down the spark?

 

[Sonreir]

Not enough that you'd be able to measure it with your eyes.

 

[headhunter8]

even with a timeing lite? i did do a omhs check on them the are at 300 ohm instead of what the manual say to be at 580

 

[Sonreir]

Electricity moves at close to the speed of light. You're not going to be able to see a difference.

 

[vagrantcycle]

Have you checked the ignition cam position. May be placed in the weights incorrectly.