ATC70 Points Problem??

[mdunn]

I have completely rebuilt my 1985 ATC70 and it still will not run. It has a new cylinder, piston, rings, cam, head, valves and carb.

I checked for spark and it had erractic spark...meaning not everytime I pulled. I pulled the flywheel off again to check the new points, and everything looked fine. When I pulled again...same thing.

So I checked the points again and this is what I found. I used the light method and applied battery power to the chassis. I found that it doesn't matter if the points are opened or closed, I always have continuity across them. Weird!

I have checked everything, and do not know why this is happening. If I take the wire off from the points to the condenser, the points work as they should. As soon as I hook up the points wire I have this continuous continuity. The insulator washers and everything are installed correctly on the points.

Any clues??!!??

Thanks for your help!

[Dirtcrasher]

Are they opening?? Are you using the light method correctly?? How does the light work - does it light up when a circuit is open or when completed to ground (I've honestly never used one, just set the gap and go,,,) Maybe I can offer another suggestion if I know how a test light works, don't mind me :lol: it's just that I use multimeters and have never used a testlight.......

I find some of the cams built into the flywheel to be so worn that they barely open. From what your saying (looking for insulating washers) that light must light when it's grounded. So you must just connect the wire from the points to your test light??

I'd pull the flywheel and physically open and close them with something and see whats up.....

I've found some points worn enough that I had to file the mounting hole oblong just to get it open to the right gap.

[mdunn]

Yep..they are opening and closing. I can physically see them and have gapped them propoerly. They are brand new. The stator plate is now sitting on the work bench. Take the points wire off and check for continuity..nothing when the point are open and continuity when they are closed...just like they are supposed to. Put the points wire back on, and there is always continuity. I don't get it. I must be missing something simple here.

The light method is simply a way to see if they are opening and closing at the right time. Connect a battery to the chassis, and put a wire to the coil output from the stator plate. When the flywheel comes up to 'F', the light should just start to go dim...meaning the points are getting ready to open. This should happen exactly at the 'F' mak...that is how you know the point are opening at the right time.

[brapp]

plan b is do what i did and just say screw it and get the cdi set up off ebay and never have to deal woith points again!

[mdunn]

brapp...how does the cdi work? No troubles? Easy to hook up? I will go to e-bay now and see if I can find what you are talking about. Thanks!

[mdunn]

My basic question after looking at this again tonight is if there should be continuity across everything on the stator plate points opened, and points closed. If I put one end of the multimeter on the black coil wire coming out at the connector from the condenser, I can touch anywhere on the stator plate and points (opened or closed) and get continuity...this just doesn't seem right to me...what is the purpose of the points then...lol

[brapp]

the cdi plate is just a entire stator and cdi and uses stock coil.

[250twostroker]

Hey I'm workin on a 70 and to get the flywheel off do I have to take that whole side cover off? I've got the flywheel loose but it hits the cover, can I grind the edge of the cover? It's an 84 by the way. Thanks!

[brapp]

it should only be 2 or 3 bolts to pullthe side cover off andthe effore to grind that out enough i foiguire it woudl be alot easier to pulla few screws/ bolts lol

[250twostroker]

Not the pull start cover, that whole side cover that the neutral indicator is in and everything? Is an 84 points or cdi? It was runnin great then now has no spark

[mdunn]

You can pull the side cover by removing the neutral indicator and removing the 4 or 5 bolts. It will come right off.

[250twostroker]

when i do that, will gears go everywhere? I dont want that to happen

[inv3ctiv3]

No you'll be fine just taking that side cover off, here is a link to the CDI

http://www.re-mx.com/mr50/mr50parts.php