No spark after rebuild, timing/points issues...

[foppert]

So after a long summer of putting together the basket case i got i am kicking it over and getting no spark at all when i pull the wire from the coil and hold it close looking for an arc. (i am assuming i should be able to see spark when i do this like i do on cars)

And i am running two VW blue coils (4 ohms, i figure i should be able to get it running on them and switch them out later if necessary)

When i set the timing i did it staticly. I have a test light attached to the negative side of the coil, and ground. I rotate the engine around the light is on for most of it, turns off, then as the LF passes it flashes fairly quickly. Does this seem correct? Both coils seem to be responding the same... which seems wrong. Like the left coil comes on as it passes the RF mark.

Anyone have tips on timing? ive watched some of the youtube videos and i have timed cars staticly before, but this is my first bike ignition and it has me confused.

 

[bcware]

If these videos don't work look to the coils and kill switch.

Make sure the wires that connect to the points are attached correctly between the insulating spacers and such.

Make sure your points are gapped correctly.

My test light turns OFF when LF or RF is reached because the points are opening.

Make sure you're setting the timing on the compression stroke.

Did it have spark BEFORE you tore it apart?

When you're looking for spark are you holding the plug against the engine? I touch a loose plug against an engine fin in low light and it will jump. It may not produce a spark if the plug is just flopping around too far from a ground.

 

[foppert]

Hey thanks for the quick response,

I bypassed the ignition and the kill switch with a jumper straight from the coils to the battery, that is hooked up to a trickle charger. I never had this engine together, i took it on as a project in pieces and now i have to finish the puzzle... which means i have no idea what i am doing most of the time, but i know these two coils both came off of running vws.

The way i was checking for spark was by disconnecting one of the wires and holding it close to ground, ill try pulling the whole spark plug and trying in the morning.

Like i said, i am fairly inexperienced with motorcycle ignitions, are both coils really supposed to respond at the same time? all the time, or do i have a wiring issue.

In the video his light comes ON when he passes the LF mark, my light comes on when i pass the LF mark but only for a split second before going off. Then it will come back on when the RF mark is passed and stay on for a bit before repeating.

 

[bcware]

No, both coils shouldn't be working simultaneously. If they are, there is a problem with your points or the wires leading to them. The coils only have two wires; one goes to each point and the other leads to, what I assume, is a power source. The "power" (I use quotes because I haven't checked a wiring diagram) wires both bridge together and share a single line on the stock harness.

My first guess would be the gap in the points. If the timing is off they still wouldn't fire simultaneously, just at the wrong time with regard to the position of the piston. If the gap in the points is too small they will touch at the wrong time and could fire simultaneously.

I made one of those videos and Mcrowell made the other. Honestly, I do not know why Mcrowell's turns ON when he passes the line. When I do my timing the light turns OFF at the moment the spark is delivered. I hook my test light up the same way Mcrowell does in his video.

The manual clearly states that timing is set so that the points just open at the moment of firing. Since the circuit is being broken when the points open the light should turn OFF, just like mine does. I set my timing again very recently, so I am 100% sure this is what happens on my 1978.

Edit:

I just checked the manual again and it also says the light should go ON when the points separate, so I am not sure why mine doesn't act this way. Mine seems to run very well though!

 

[foppert]

Its the way that you hook up your test light why it goes off. I have a book that explains both your way and mine. You hook yours up to a source of power and the points as ground, while i hook mine between the negative side of the coil and ground.


So my test light reads 5.6 ohms, while my coils read 3.8/9, this would explain why i it appears that my coils are firing together, the power is shorting the whole bike through the ether of the coils and the points if one of the points gaps is closed. My test light can only see if both are open or both are closed because it has more than 4 ohm resistance.

EDIT:
Checked spark, using your method... nice fat blue spark. Kicked it again this morning and started right up...
Thanks alot for your help bcware.