ATC70, no spark, help!!

[danney f]

I know theres not much to the electronics on these things, so this might be a simple fix. I have no spark at the plug. The run switch is good and so is the coil, so how do I check the rest of the electronics on this thing and what else is there to check. I appreciate any help, thanks.

[jerry-89-250R]

did you check the stator, easiest way is unhook the 2 wires, connect a volt meter to them, switch volt meter too DC, pull the rope a few times. it's been a long time since i messed with them

[danney f]

If I remember correctly, there are like 3 or 4 wires comeing out from there. So which ones do I check and what should it read on the metter? Thanks for the reply.

[jerry-89-250R]

what color wires, it's been a long time, i'll help if i can, all your checking is really a coil or 2 coils, it may have a exciter coil, take a ohm meter first and see if you can read between them, let me know the colors it might come back too me, what year atc 70, my son had one from 5 years old till he turned 10, i had every 3-wheeler honda made over the years,

[CBW]

what year is it.........i had an 85 and an 84,,,,,,,try checking the points behind the pull starter and then behind the flywheel..........

if the points are worn, or have a raised spot, or are out of adjustment,,,and do not break contact,,,,,,,,,,,,NO SPARK.

[danney f]

It is an 85. I don't have to pull the flywheel to check the points do I? Can I check them through the holes in the flywheel? I'll take a better look at it tomorrow and get back on here to let you know what I found. Thanks for all the help guys.

P.S.
What should the points be gaped at?

[2K1 300EX]

I just tore my '85 70 3 wheeler apart 2 days ago to get it running and to paint some stuff on it, it's been sitting up for 10 or 12 years. I will look at it tomorrow and see what wires you need to check.

[danney f]

Once again Thanks for all the help so far. I ride/love this little wheeler just as much as my kids if not more and would love to get it running again.

[CBW]

Originally posted by danney f
It is an 85. I don't have to pull the flywheel to check the points do I? Can I check them through the holes in the flywheel? I'll take a better look at it tomorrow and get back on here to let you know what I found. Thanks for all the help guys.

P.S.
What should the points be gaped at?




you can check it through the holes..........but obviously to replace them you need to remove the flywheel............


to check the gap ,,,,,you can do it with it on but i never knew the gap distance,,,,,,,,,,,,i was instructred to set the points to open up just as the indicator in the case top points to the "F" on the flywheel

[danney f]

Thanks I'll work on it later today and let everyone know what I found out.

[danney f]

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?

[jerry-89-250R]

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

[danney f]

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.

[jerry-89-250R]

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

[danney f]

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?

[jerry-89-250R]

have you tried un-hooking the kill switch

[danney f]

Yup, we disconnected it and I even took the switch apart to see if it was broken and its not.

[jerry-89-250R]

if your sure your stator is putting out voltage, amd your points are clean and working that only leaves the condenser or the coil

[danney f]

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.

[jerry-89-250R]

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?

[2K1 300EX]

Originally posted by danney f
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?

I have the same problem on mine, no spark. I forgot what wire go where..if I dont' have a headlight hwere would the dark green wire go?

[danney f]

Its still has good compression. The thing I can't figure out is why I only get fire at the plug when I flip the run switch back and forth while pulling on the rope? The reason I know it needs new rings is it smokes when first started.

[jerry-89-250R]

it sounds like something is shorting out too the frame ground, do u have access to another coil? try unhooking you coil and test it with your ohm meter again, this time check it on the 1k-2k scale, you should have some resistance, if it reads 0 your coil is shorted, the buzzer on your meter only told you the circuit wasn't broken, when you checked the black wire too the ground and got a reading was your points open or closed?

[2K1 300EX]

I looked at the wiringon mine today.....I have 2 black wires and a dark green and a light green w/ a red stripe coming out of the case by the pull rope. All the wires are in a rubber sleeve except the one of the black ones. the 3 in the ruber sleeve go to the fusebox then from the fuse the black one goes to the coil. What is the other black wire that goes nowhere for?