Help- Cant get spark - Exciter 570

[harley sled]

I'm fishing for ideas- I've tried to go thru the repair manual trouble shooting but still haven't figured it out.
I do not get spark at the plugs.
I have 2 different coils that I have tried
Both coils show some secondary coil difference from the book values but they are not too far out of whack. They are both about twice the resistance listed in the manual when checking the spark plug wires.
I guess I'm thinking that this should be close enough to get some spark.

(Let me know if you think this is enough different to make the difference of not running.)

I've pulled the wiring plugs on these items as indicated on the manual
I have checked the key switch and get black and black/white continuity and disconuity as shown in the repair manual.
The kill switch seems to give the proper info
The throttle switch and carberator switches seem to give the proper info
I've checked the source coil resistance is 500 ohms as indicated on manual
Pickup coil shows 15 ohms as indicated in manual

And I got another used CDI unit which came from a working yamaha being parted out, and it does not seem to make any difference- still no spark.

Also - should the headlight come on when the key is turned to ignition, or only when it is running?

 

[Disco Dan Richter]

Sounds like your internal coil is bad, it happens a lot on the oldies, exploders were good for that.

 

[harley sled]

source coil

I thought that also, but

According to the manual the source coil is supposed to have from 500 to 612 ohms, and reads 500 ohms

The pickup coil is supposed to read 12.6 to 15.4 ohms and reads 15 ohms

Both of these are reading what they are supposed to.

 

[Sammy]

Try isolating all switches from engine (ignition, kill etc) by disconnecting single black or black/white wire coming out from stator. This is usually a single wire connector and is found where the harness first exits the stator housing. disconnecting this will eliminate all kill devices and help isolate problem. Just a note, source coils were a problem on the early yamahas and could be hard to identify. Resistance tests are helpful but if a load is not applied to the system they are not always accurate. Hope this helps.

 

[0007]

When it comes to testing a pick up coil (pardon the pun here but) Resistance is futile
You need to test "Peak Voltage" if you dont have the Yamaha adapter you need to compare it to a known good unit
Yamaha adapter should show you about 5v Open (meaning unplugged), test the power source coil the same way and should be 45 - 75v or so
If you have a meter with a hold function you can use that but you need to test a known runner and see what it makes

 

[harley sled]

thanks to all for the help-
I think we decided that the stator is goofy
voltages are not right

super- I'm considering this post as completed