To spark or not to spark

[Nuthinspecial]

I finally found a decent ATC 70 for a decent price!

The guy I bought it from said it was running a few days ago, but then just quit when the kids were riding it. He checked the spark plug and it had no spark.

Anyway, I figured it would be an easy enough fix so we agreed to drop $100 for the hassle and I bought it.

If I grab ahold of the spark wire and pull it zaps hard. When I put a plug in it (three diff. brand new ones) no spark at all. He seemed like an honest enough guy, and I really don't think he was trying to screw me...I think it's something simple and I'm just not bright enough to figure it out.

Doesn't make any sense to me though...either you have spark or you don't...It's not like I have weak spark either. I stuck my multimeter into the end of the spark wire to make sure juice was going through the elbow piece. That shows everything is fine, but still when I put the plug back in the wire and ground it to the engine.....no spark.

Any ideas?

[Fuzzy]

It sounds like it is the elbow giving you greif. Have you tried holding the elbow next to the engine with no plug in it. And pulling it over. And see if a spark jumps from either the wire or the elbow. Or if it is a removeable elbow. Just take it off and wrap the wire right around the plug and try it.

[dads]

Does the spark make your eyes light up if not its too weak. may be coil or the pulse coil.

[Nuthinspecial]

Yes it is a removeable elbow. I tried wrapping the wire around the plug and holding it with a pair of pliers (I don't have any vise grips anymore...usually more damage caused than good) and didn't see anything. Maybe I can talk my wife into pulling the rope for me so I can get a better grip and look.

Will it really jump a spark from the elbow to the engine?

Thanks for your help Fuzzy.

[Nuthinspecial]

Dads,

Yeah the spark was plenty strong! I have carpal tunnel syndrome in my wrists real bad and that spark jolted to my shoulder....my elbow was sore for an hour!

[Fuzzy]

Yep you have to really look hard to see the spark. Doing it in the dark is best. They are not like a high energy car ignition. But you could try putting the plug back in it. With the wire wrapped around it and try starting it. They will start with a lot less spark then you would imagain.

[dads]

Is it a copper core wire . i had to replace one it had a brake in the wire . some times people change to a graffite ( car wire) they brake down to quik. its the cheep fix.

[Nuthinspecial]

Well, I don't know a thing about spark plug wires, but this one...which looks original, but who knows.....has several smaller wires inside the black insulation....like maybe 5 or 6 strands?

The elbow is a screw on and looks new....and definately not original. I was thinking about stripping some more of the insulation back to see if there are more wires that broke off, but then I'm afraid the plug wire would be too short to reach the plug. I'm sure someone has done something similar to this before on this trike, but the main plug wire and the coil look to be original. I think maybe the original wire cracked or broke and someone shortened it in an effort to get to some good wire without replacing it??? Maybe I need a new wire.....can you get one or is it all one piece with the coil?

[dads]

The wire unscrews from coil it maybe sealed in but will unscrew. If sealed in scrape it out but stay to the edge the screw or pin is in the middle like the plug cap. the wires usually break in the bend in the wire. will be really flexible at break. if you pull the wire out put the plug in coil ground with wire kick over see if plug fires if no fire has to be weak spark.

[Nuthinspecial]

Weak spark it is! Damn it! Well, it'll have to wait till next week now. Thank you guys for all the help and advice! :thumbsup:

[dads]

Well now your at step two fineding out if its the coil or pulse coil. I would piont to the coil first ,you can test with ohm meter. or if you know some one with a working coil borrow it. if it work you know what is bad if not you will know its the pulse coil.

[Nuthinspecial]

I'm gonna cheat and take it to Randy down at MMS on Monday....he has helped me out in the past with stupid stuff like this....usually only a couple bucks and a day or two wait. I just don't have time to keep fiddling with it, and my daughter wants to ride the trike I've been promising her for three months! Now I finally have it and she can only look at it. :ugh:
Once this one is done, I'll have to take some pics, it looks like my 200's bred in the barn and had two little ones! :D

[hrc200x]

My cousin just got two Honda CT 70 mini bikes, they should be very similar to the atc 70's. Both of them needed the points adjusted to run right. They were very touchy to adjust too.

Another thing we found out when we were working on them was that if you test the spark plug wire with a test light it won't light up even if you have good spark, but if we tested the only wire that goes into the coil with the test light it would work.