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1978 DS100 Stator issue

Posted: Wed Aug 26, 2015 8:55 am
by singring
Engine was running just fine, then out in the middle of a trail ride it went dead. I have bypassed the engine kill switch in my diagnostics, and ,if I am correct, the issue is at the magneto stator plate. All wiring appears to be good, no grounding issues between components of the stator. I am wondering if the primary stator coil is toast. The resistance I get across the coil's terminals is 2.5 ohms. I don't know if that is within tolerance, as I haven't been able to find info on it yet. Anyone know what resistance is acceptable?
Thanks

Re: 1978 DS100 Stator issue

Posted: Wed Sep 23, 2015 5:57 pm
by singring
I have placed an insulator, a business card, between the contact points of the stator's contact breaker and found I have continuity across the points. If I disconnect the wires from the contact breaker's terminal and do the same test, I have no continuity across the points. Using alligator clips I connected a spare contact breaker to the stator plate, and the wires to the spare's terminal. I did the same test with an insulator between the points, and I get the same result....so the fault is not with the contact breaker. I am stumped...
somehow there is a grounding issue with the stator plate, the stator's wiring, or one of the stator's other components. I am having a devil of a time tracing this bug.
Any help appreciated

Re: 1978 DS100 Stator issue

Posted: Wed Sep 23, 2015 6:49 pm
by jabcb
Your ignition circuit should be something like the one for an RV125B.
download/file.php?id=1868

With the ignition coil, kill switch & ignition switch disconnected.
With the points & condenser disconnected.

Check the resistance across the primary stator coil.
Check the resistance to ground for each side of the stator primary coil.
One side is grounded & you should get zero for that side.
(You actually don’t quite get zero, you get the meter’s internal resistance.)

Do the same tests for the ignition coil, primary side.

Not sure what setup you have.
Post a pic of the magneto/points someplace like photobucket & provide the link.