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post #1 of (permalink) Old 10-20-2005, 12:00 PM Thread Starter
 
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72 Yamaha DT250 not getting spark

How do I test the ignition coil on this bike? I really haven't touched it since it stopped running 4 years ago.

It has about 20 hours on a new top end, points, condensor....

It is a fun bike and I would love to fire it up again.
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post #2 of (permalink) Old 10-20-2005, 03:34 PM
 
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Re: 72 Yamaha DT250 not getting spark

I'd replace the points and condensor before suspecting the ignition coil.
OD
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post #3 of (permalink) Old 10-20-2005, 08:44 PM
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Re: 72 Yamaha DT250 not getting spark

I agree with originaldirt-the points and condensor are essentially wear items and have quite a bit of age by now. But, if you feel that you must test the coil, you can use a 12v battery to do it. Run a wire from the negative on the battery to the frame of the bike. Then, run another wire from the hot side of the coil. With a known good plug, rest the threads of the plug on the engine case. Next, quickly touch the wire from the hot side of the coil to the positive terminal on the battery and watch for spark on the plug. You must just very briefly and quickly touch the wire to the terminal to simulate the action of the ignition system. That is, touch, remove, touch, remove. You'll get the idea...

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post #4 of (permalink) Old 10-21-2005, 04:19 PM Thread Starter
 
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Re: 72 Yamaha DT250 not getting spark

The points and condensor only have about 20 hours of riding time on them. Do you think they could go bad that fast?

Thanks for the advice on testing the coil, I will do that this weekend.
Will
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post #5 of (permalink) Old 10-21-2005, 05:21 PM
 
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Re: 72 Yamaha DT250 not getting spark

The problem with points/condensor systems is that they are good for 1 ride, 1 day. 1 week, 1 month, 1 year, or more. The life is indeterminate. Try to clean the points with a clean piece of white paper inserted between the closed points and carefully dragged out. DO NOT FILE or use abrasives to "clean" the points. They used to sell "contact cleaner" but that stuff was an EPA hazard, the stuff available today rarely cleans, often takes forever to dry and is quite flammable should the points make a spark at their contact point.
OD
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