Ok this is what I've found out. There are three wires coming out from the bottom, one dark green that runs up to the headlight, one light green with a red stripe that goes nowhere and a black one that runs to the coil and run switch. I used my multimeter and tested the run switch and it was good. I had the meter set on ohm with alarm to where it would buz when the probs made contact with each other(as you can tell I'm not real good with these meters). I than unpluged the black wire, touched a prob to it and the motor and got a signal(am I suposse to?) How do you check all of these parts and what do I need to set my meter to to do the test?
a little more info please, 3 wires coming from the bottom of where? does it have points or a cdi? and i don't remember a headlight on my son's atc 70, but that was 13 years ago and i've forgot a lot since then, i'll help if i can
It has points which I have adjusted to where they open when the "f" on flywheel lines up with the "-" mark on the case as suggested. The 3 wires are coming out of the case by the pull rope. And some 70's had the headlight and some didn't. Some also had 3 speed's and some had 4speed's which is what this one has I think it just depends on the years. I don't know if this help't anymore, just let me know and I will try to add any info I can.
i know the 85 had a 4 speed, our's had a blue seat and blue # plate where a headlight would be, trace down the light green wire w/stripe it should go too your headlight, the black wire should be coming from you points to coil and kill switch, try reading between the dark green and light green with stripe, set you ohm meter about mid range 5-10k, see what you get, also did you clean the points with a fine piece of sandpaper,also check too see if your stator is still magnetised
Ok I finally had time to work on this and this is what I found. The only way we get fire at the plug is if while someone pulls on the rope, you turn the switch from run to off, back and forth real fast. Could it be that something is not breacking contact when it should? I checked and cleaned the points and they open when the "F" lines up with the mark on the side case as sugested. O we tried with it in run and with it in off, we also tried putting the switch in between the run and off, nothing. Any ideas?
I get fire at the plug when I flip the switch back and forth real fast while pulling on the rope. I wouldn't get any fire if the stator and coil wasn't good, right? It needs new rings so I geuss I'll just buy a tune up kit while I'm at it.
you may have just found your problem, for a engine too run you need 3 things- fuel-spark-COMPRESSION, how does the spark look, and is it on the center of the plug, does the atc have any compression?