I've finally met my match on this one. After replacing the source and ignition coild on '89 yz 80 I still can't get it to run. Top end is fresh, carb clean, air filter clean. Ignition system checks out per the factory manual. Spark seems good but occasionally intermittent (sometimes you can kick it 12 times and get 12 sparks, other times 10 kicks gives you 1 spark). Is there anyway to test the CDI black box short of buying a new one. I have nothing left to try.