Weak spark

[ZombiePotatoSalad]

I just got my new ignition coils and air filter, bike still won't start. I took out each spark plug and plugged it into the wires, then laid it on the engine and cranked it. I saw a spark, but it looked very faint and white. I had to look closely to see it. I'm wondering if this is the cause of my no-start woes. The fun part is tracking it down... and I don't know much about electricals. I have a multimeter.

[salty_monk]

WHat coils did you get? Stock? Dyna? First see how many volts the coils are getting, you may have to add in a relay to make sure they are getting 12v. Weak in... Weak out.

[ZombiePotatoSalad]

I got these, the specs weren't listed. How exactly do I check that?
https://www.ebay.com/itm/Motorcycle-...3c74%7Ciid%3A1

[Redman]

Check voltage at the coils. Have meter positive on THe org/wht wire and meter negitove on ground.

And while you are at it, check battery voltage with engine off, and with engoine at about 4k rpm.

[ZombiePotatoSalad]

Check voltage at the coils. Have meter positive on THe org/wht wire and meter negitove on ground.

And while you are at it, check battery voltage with engine off, and with engoine at about 4k rpm.

At where the screw connects to the coils, or what? And I can't get it started, I'm trying to figure out why.

[tom203]

Put your multimeter on 200 ohm scale....connect the meter probes to those green wires with bullet connectors ...be patient, meter will swing up/down but should settle at about 4 on display....this means the coil has a 4 ohm primary resistance .

[ZombiePotatoSalad]

Put your multimeter on 200 ohm scale....connect the meter probes to those green wires with bullet connectors ...be patient, meter will swing up/down but should settle at about 4 on display....this means the coil has a 4 ohm primary resistance .

Ok, it showed 4 ohms. So these coils should have enough resistance.

[tom203]

Ok, it showed 4 ohms. So these coils should have enough resistance.

So far so good... Now find the orange/ white wire that is the 12 volt positive - it splits off and connects to a terminal on each coil. On DC voltage scale on meter, put one meter probe on this orange/white wire at coil connection and other meter probe on a good bike ground, frame, or battery negative. Crank starter over and note voltage reading and report.

[salty_monk]

Report the voltage before cranking and whilst cranking. It would be best if you used the battery negative (-) for your ground.

Also report the voltage directly at the battery before cranking and whilst cranking (out the probes directly on the battery terminals).

you should also make sure that the main ground wire going from battery to the motor (black) and the other ground wires going to the frame (black white) are clean.
I will sometimes add in an extra large 6 or 8 gauge ground wire from the battery to the frame somewhere up near the battery box and then sometimes add one from the side panel where all the electrical boxes are back to that.

[ZombiePotatoSalad]

That will have to wait. I had to pull the plugs off the wires (the plastic boxy ones) because they didn't fit well with the plugs on my new coils. However, one of the bullet connectors was stuck in the plug, and further attempts to extract it broke it. The spark plugs for #1 and #4 cylinders aren't sparking. 20190830_143013.jpg

[tom203]

You need good connections.. If bullets don't work, switch to male/ female spades with careful crimping. Hopefully, 1 and 4 will come alive.
Sadly, the 550 ignitor has poor record, but test thoroughly before assigning blame

[ZombiePotatoSalad]

What else can I test? What is the ignitor? You mean the starter? I'm also thinking of checking the stator.

[ZombiePotatoSalad]

You need good connections.. If bullets don't work, switch to male/ female spades with careful crimping. Hopefully, 1 and 4 will come alive.
Sadly, the 550 ignitor has poor record, but test thoroughly before assigning blame

The multimeter says 9.33 while the ignition is On, but ~7.19 while cranking. This is coil 1 (1&4).

Coil 2 is something of a space oddity. While the ignition is On, it reads 0.04 (but jumps to read 10.64). When cranking, it goes to 7.45.

EDIT: Depends how I hold the probe for coil 2's reading. The bullet connector is broken. I just might replace the lot.

[tom203]

We are looking at weak spark issue here, so ,at the moment, don't worry about starter motor or stator (the gizmo that charges the battery when bike is running). The ignitor is a little box that tells the ignition coils when to fire - it gets a signal from the signal generator coils mounted on right end of crankshaft.
Fix your connections and repeat the voltage tests, both before cranking and during cranking.

[ZombiePotatoSalad]

We are looking at weak spark issue here, so ,at the moment, don't worry about starter motor or stator (the gizmo that charges the battery when bike is running). The ignitor is a little box that tells the ignition coils when to fire - it gets a signal from the signal generator coils mounted on right end of crankshaft.
Fix your connections and repeat the voltage tests, both before cranking and during cranking.

I thought the stator also affected the spark.
What about the solenoid? Does that affect spark as well?

Also, the positive wire is always white, right?
Negative is orange?