No spark

Note the factory swapped the swich clusters over duing 1972. The wire colours/colors and switches remain the same just on different sides.
 
Thanks LAB. At this point, I’m not sure what I’m dealing with. The y/w wire top button on left side is the kill switch. I’ve got power there unless you push the button. It was disconnected. There’s a b/w wire to w cluster under tank but it’s male. I just don’t know where the kill switch wire is supposed to go. No b/w per diagram.
 
FL54 said:
Thanks LAB. At this point, I’m not sure what I’m dealing with. The y/w wire top button on left side is the kill switch. I’ve got power there unless you push the button. It was disconnected. There’s a b/w wire to w cluster under tank but it’s male. I just don’t know where the kill switch wire is supposed to go. No b/w per diagram.
Click to expand...
Kill switch is wired in series from ign switch power through to points plate I believe. So it interrupts points power when pressed.

You can fit a bypass switch direct from battery to points if you just want to confirm the problem and or fire up bike.
 
For points the white/yllow should connect to white/blue to the ballast resistor that connects to both coil negative terminals through a white/purple wire then either a black/white or black/yellow from each coil positive to each points set and one condenser each.

Early switch layout.

Later layout.
 
FL54 said:
Some progress. Yellow/ white from left control is kill switch and found disconnected. According to the wiring diagram, it should connect to Blue/ White wire in main harness. Only B/W wire in main harness is connected to the white block that already has voltage. Hoping to find b/w female empty but not there.
Click to expand...
Based on what you have just described above.... The Yellow/White should be connected to the Blue/White but instead the B/W is connected directly to the White which means the kill switch has already been essentially bypassed. The Blue/White is the power to the points through the ballast resister. Check connections of the B/W wires at the ballast resister under the tank. Also, Yellow/White is considered White/Yellow and Blue/White is White/Blue
 
Last edited:
Cuppy said:
Also, Yellow/White is considered White/Yellow and Blue/White is White/Blue
Click to expand...

Yes careful how you refer to the wires as there's also a blue/white wire (sorry, headlamp main beam wire) although in the headlamp shell and one switch cluster harness. If the kill switch has been bypassed then white should be connected to white/blue as described.
 
Last edited:
I really appreciate the help from everyone. I’m still at a standstill. No voltage to points although everything else works. I now have to put everything back together unresolved and trailer the bike back to the DMV. Don’t you love bureaucrats? To be continued. Hopefully, I can get it resolved with everyone’s help.
Cuppy said:
Based on what you have just described above.... The Yellow/White should be connected to the Blue/White but instead the B/W is connected directly to the White which means the kill switch has already been essentially bypassed. The Blue/White is the power to the points through the ballast resister. Check connections of the B/W wires at the ballast resister under the tank. Also, Yellow/White is considered White/Yellow and Blue/White is White/Blue
Click to expand...
Sorry to be confusing. It’s a white/ blue in the white cluster not b/w. It this point, all that I’m seeing is red.
 
If you have been messing about with the points then a common issue is putting the insulating spacer back in the wrong position and the result is no spark.
 
Make sure the points plate mounting screw or washer is not touching the points leaf spring
 
As noted, it is very easy to attach the wire to the points incorrectly so they are grounded. If they are mis-connected that way, no voltage would show at that points. BUT if you have static timed it with a bulb or meter, that wouldn't be an issue. OTOH if you had static timed it the old way - with cigarette pack cellophane, it could be!! :)
 
Yes as others have said ensure the points wires are fixed under the insulators against the springs as below not under the nuts above.
 
it doesn't matter how the points or hooked up, or what wires go where at this point, IF, like you say, you have no current TO the points. Your 1st step is to find out why that is- not trying to make light of your issue, but you have to start with the 1st step- you state there is no power to points, then leave it like that.
 
Thanks Bert. I will check but not sure that’s the issue. New facts. W /blue wire is getting power from white cluster under tank. Power via w/blue to ballast resistor. No power from ballast resistor to - side of coils. I was hesitant to bypass ballast resistor as I know the coils are 6v.
 
Have a confession to make to everyone. Even though several folks responded to this thread advising to check the wiring of the points I discovered that I had put the insulating washer under the point wires. I had replaced the points plate because the adjusting screws were badly buggered and wired it wrong. I did it so long ago that I had forgotten it. After seeing the diagram that LAB posted, I rechecked and found the error. Wired it correctly and the bike fired up. Apologies for spending so much of everyone’s time on this and in the end it turned out to be pilot error. However, I let the bike warm up a bit and decided to dynamically time it to check my static timing. Turn the key back on and no ignition light. All the other lights work so I’m at a loss as to why this happened. Apparently the gremlins haven’t been totally exorcised from the bike. Out of town now and won’t be back until tomorrow afternoon so see why. Again, my apologies and thanks for all the guidance.
 
No worries Mate!. We all learn.
This post will probably help someone down the road.
The original assimilator is quite finiky.
If you haven already, pull the tank and go through every connection.
Replace/upgrade connectors as necessary.
Double check all grounds...the ground at the head steady is a common problem.
May or may not need a new assimilator...
 
MichaelB said:
No worries Mate!. We all learn.
This post will probably help someone down the road.
The original assimilator is quite finiky.
If you haven already, pull the tank and go through every connection.
Replace/upgrade connectors as necessary.
Double check all grounds...the ground at the head steady is a common problem.
May or may not need a new assimilator...
Click to expand...
Thanks Michael. I’ll check it when I get home. Hopefully, an easier problem to troubleshoot.
 

Similar threads

C
No spark!
Replies
17
Views
1,370
DennisMo
D
WEM
No spark
Replies
11
Views
1,783
concours
concours
PatMat
Spark Plugs do not fit
2 3
Replies
50
Views
2,981
JimNH
J
YING
Tri-Spark question
Replies
10
Views
453
Schwany
Schwany
D
Can you look at my spark plug colours and suggest a path forward for tuning my Mikuni ?
Replies
14
Views
626
Torontonian
Torontonian
Back
Top