I have two ATC 70's I am currently working on to give to my kids for Christmas. One is an 85 and the other an 82 and both had been sitting for quite a while before I picked them up and got them running. So far I have done the usual, cleaned and put rebuild kits with new floats in both carbs, new NGK spark plug boot ends and plugs, gapped the points, checked the valve lash, changed the oil. A couple of weekends ago was the "trial" run for both with me taking them out to my parents place in the country and letting a total of 6 kids give them hell for the better part of the weekend to let whatever is going to happen happen with them being they had been sitting. Well the 82 was the first to go Saturday evening losing spark. Pulled on it to the point I broke the pull rope so put it aside. Sunday the 85 was the second to go with the same, no spark. I ordered new points, condenser, plug for both which seemed a pretty decent kit at about $30 for each. I then purchased what was advertised as "universal" coils for both as well. This past weekend was the first I got to even mess with them and I only ended up getting to the 85. To my surprise it actually fired right up first pull. I rode it around and all seemed well, so decided to go ahead and do the coil swap being my flywheel puller hadn't made it in yet. Coil was identical and direct swap, but no fire. Tried everything before swapping back in the original and fired right up. Turns out the seller comes back and says its a 12v and not a 6v coil. Would have been nice to have that info listed in the description. Anyways, I let it run for about 20 minutes at idle, couple of revs here and there, seemed solid. Shut it off and cleaned up the garage and work bench. About 2 hours later I fired it up and went to take it down the block. Got through all 4 gears, ran good, headed back to the house and dropped dead. No spark again. It does now have the original coil back on it, so am guessing this is what happened to the kids the other weekend. What would be making the spark come and go with basically all the original firing components now again? I have read up on the neutral safety switch and have not tested that yet, but could there be anything else? Do the stators go bad just like that? I did try pulling on it again when I got home from work yesterday and there is for sure no spark at all now, hot or cold. Want to make sure I am looking over every possibility while I have them apart changing the points etc. Thanks!