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Discussion Starter #1
This is on a 1974 Honda 125XL

Ignition Coil Leftmost (1 pin)

Advancer second from left (1 pin)

Gearbox second from right (4 pin)

Battery Rightmost (4 pin, Positive, negative and a loopback)

I have just confirmed that the ignition coil works, Now I am trying to figure out if the advancer does as well before I tackle the proper wiring harness.

I figured the easiest way to do this would be to get the spark plug to light by kicking the starter over.

So how would I wire this to do that?

Thanks.
 

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If you take the cover off the points/advancer, and the cover that says HONDA off the engine, you can verify the points are operating. Under the HONDA cover is the flywheel/rotor, which has the timing marks, and a bolt in the center that you can turn the engine over with - easier with the spark plug out. There should be a pointer and marks on the rotor to indicate Top and Fire positions; when the pointer points to the Fire mark, the points should just begin to open on the fire cycle. When the points are closed, the white wire should measure to ground/engine case, and when lifted by cam part of the advancer, no connection to ground.

The white wire should go to the coil and condenser common connection, where you should find a socket to mate the bullet connector, and the other wire (black or black/white) from the coil should go to the battery power from the key switch, which should also be a socket; if your bike has a run/stop switch, it would go through that to the key switch.

The connector next to the shifter looks like the output from the generator stator, and probably also has the neutral switch output.

The connector at the battery would go to the key switch to power the coil and lights. I don't see any rectifier or regulator connected to the battery; it would connect to the stator connector and to the battery to keep the battery charged.

You may want to search for a wiring diagram, to see how all that is supposed to work.

Also, if you add your location, you may find someone to drop by and show you how it works.
 

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What you have pictured is the advancer and points cam. When the engine is running, the weights with springs attached rotate the cam to change the amount of advance. That cam is what the cam follower on the points rub on for most of its rotation; the portion that dips in is the region the points are closed, charging the coil with current, so when the cam follower hits the higher part of the cam, the points open, and cause the spark.

You need a points plate with points to complete that setup. Please read the page I provided the link for, on your other thread.
 

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Discussion Starter #5
I am hoping this is the 'points plate'.

As well to check my understanding does this whole module basically act as a ground that toggles itself based on the rise and fall of the piston, therefore only allowing for a spark the the desired time?
I apologize for the dumb question and I am very grateful for the help!
 

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Yes, that is the points plate. The wire connects to the spring through an insulated standoff, so it is not connected to ground until the pivoting part closes the contact breaker (points), opposite the wire connection. Your photo shows the rubbing part of the pivot just on the high part of the cam, so the contact points should have a gap between them. What that gap should be is, in the service manual; for my CB450, it is 0.012-0.016". The gap is adjusted by loosening the two screws on the plate that hold the points assembly to it. Timing is set by rotating the whole plate, then tightening the two screws that hold it to the engine.
 

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Discussion Starter #7
I managed to sort it out with this article:

https: //advrider.com/ index.php?threads/honda-xl-troubleshooting-spark-issues.427583/

One point of confusion, I have narrowed the problem to be the coil, as I blew two leds testing the alt (steady light), and advance (flashing light). However I can make the coil spark when scraping a positive lead on its protruding wire.

So is my coil just worn out or am I missing something?
 
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