PDA

View Full Version : 1985 ATC70 No spark..


Mike_Ham_250R
07-23-2009, 11:18 PM
Decided to dive into my project already so that this thing will be up and running soon. I pretty much have it narrowed down to not producing spark. There is electricity that goes through the plug wire to the plug because I was able to shock myself by placing a test light in there and grabbing the end of it. If you hold the wire to the engine you can see a small spark jump from it to the engine.

I have a brand new NGK plug gapped properly so it isn't that. I took an ohmmeter and when I test the ignition coil I took a prong to where the spark plug wire connects to and I tested all of the terminals and everything came up OL for open line. Does this indicate that my coil is bad? Thanks.
atctim
07-24-2009, 08:59 AM
If it has not been run for a while - start by cleaning the points. That will give you a stronger spark.
Dirtcrasher
07-24-2009, 01:28 PM
Mike - Not sure if it's your issue but the 3 70's I messed with recently were all a PITA even though they had some spark. I couldn't get the right size gap because the points were too worn out, I actually elongated the adjusting hole to get the right gap.

The other 2, I just bought 2 new sets of points and condensors at SH. Your dealer will soak you double or more than SH......

Between the points and the carbs of these 70's, I honestly find them tougher to tune than any ordinary 200 or 350X etc :D
night4creeper
07-24-2009, 09:05 PM
85 model should be CDI, both mine are. if you don't have it already download the manual from this site. it will help you test out the elec. components.
jcorkin
07-24-2009, 10:49 PM
all 4 of my 70s dont have a cdi and they are all 85s...................but points are a big problem with these little guys i would go to dratv.com and order a new set, regardless of it being the problem or not it is a most on these guys, the old points suck and the new ones are a lot better but anyways the points can still create enough energy to shock you as the human body only has roughly 200ohms of resistance and a spark plug has to jump a gap of infinite resistance so it is def a good place to start.