No spark, no go

[steve24265]

I'm new to the forums and I'm in information overload. I have a 84 spree (nq50) and there's no spark. I bought it a couple weeks ago, I'm probably the 5th or 6th owner. I've had to clean up a bunch of wiring due to previous owners attempt to get it running. I've downloaded the service manual and gone through the checks inll trying to determine the lack of spark. The ohm testing shows everything with Honda specs, except the exciter coil. My multimeter shows open loop. Does the battery need to be connected to get a reading for this coil? I have it out currently. Or does this mean I have to aquire another alternator? I also have an 83' tact, from what I can tell. It has nb50. It has spark, so I was thinking of using that as a donor. Are certain parts interchangable?

[Meatball]

Many things could give a “no spark” situation. Since the wiring is already in question, thats a place to start looking.

Does the rear taillight illuminate when the key is switched to ON? It needs to be.

Is the button set to “Run” on the switch near the throttle grip?

Its possible the CDI is bad and theres no way to test it. Try swapping the CDI from your Tact if it has the same connector. Im not familiar with the Tact’s.

Is the inline fuse good? Its on the positive wire downstream from the battery a bit. I think it sits in a pocket on the battery box.

The ignition coils are known to go bad sometimes. Or the tiny clip falls out of the boot and now wont make good connection to the spark plug. Just a thought.

You can trace backwards with a multimeter from the coil itself while cranking the starter. See if youre getting a reading.

[steve24265]

I just wrote a long reply and I lost it.

Taillight is illuminated with I turn the switch to on, the run switch is set to on, the left brake is pulled in and locked. No spark
I used the wrong setting to check the exciter coil, it tests to 1800ohm
The resistance on the primary coil is about 1ohm and when I test the green to the end of the spark plug wire (with the boot off) it's an open loop. I have an extra coil I bought last week and it has the same result. I know the levels for then are much higher than what the book shows
I did cdi the swap from the other scooter and same results, no spark

There is no inline fuse, the PO spliced a lead from the battery directly to a red wire which I think goes to the ignition switch. The other red lead good to the starter relay

Where is the rear stop switch? The schematics show one.
When I cranked over the engine, the reading from the exciter coil was all over for resistance. Is that normal?

I hope my ramblings make sense

[Meatball]

Mousewheels is the resident wizard on wiring gremlins. He knows the schematics so well you’d think he wrote it. If the PO cut and spliced some stuff, good luck with that. Figuring out what he did and how to undo it is something I dont have patience for.

If it were mine, Id strip it to the frame, buy a good used harness and replace the whole d*** thing. Its cost prohibitive, labor intensive and might sound silly to go this route…but I dont have patience for shade tree wiring jobs. Thats just me tho.

[steve24265]

Found one on eBay for $30 with shipping and I now purchased it. I did come across a seller on Amazon that looks like they're selling original parts and they look used too.
Stripping to the frame is something doesn't seem to hard, I already have most the panels off. Just can't figure out around the headlight area, do I need to take off the handle bars to remove it?

Unrelated topic, is there a thread on repairing body panels? The bottom panel has a crack

[steve24265]

Another quick thought, how important is the battery size? I'm using a 12v3ah battery, because that what Amazon showed for the model. The book shows to use a 12v4ah. I didn't have the book yet when I bought the battery. The 4ah is a little bit taller than the 3ah, will it still fit without any issue?

[Meatball]

4L-BS is the correct battery. Cheap $20 ebay deal. Any ah will work.

[steve24265]

That's the battery type I have, I didn't know if amperage was a big deal. I've gone through and checked continuity everywhere. Everything is within Honda specs. The cdi unit I have does work, I checked it on the nb50. I even had my mechanic neighbor come and we checked continuity again. He thinks there's probably a frayed wire that's not carrying voltage. Has anybody come across having frayed wires? He was going to talk to his buddy at work that's the 2c expert I decided to add an inline fuse since the PO removed it. It's not on the lead that goes to the starter relay. When I connected the leads back to the battery, I heard a bunch of clicks. But still no spark. Does the regulator/rectifier have anything to do with a no spark? Would I still get spark if the stator was removed and reinstalled incorrectly? If the timing was off, would cause a no spark? How many of the accessories need to be connected? The bystarter and the instrument cluster are removed. All the lights, except the taillight are removed. I found out that the horn doesn't work, I get no reading on the multimeter. I'm going to try hooking it directly to a battery tomorrow.

[steve24265]

I figured it out!!!! Watch a YouTube video for generic small engines and they said .010' min gap and a max of .030". The pulse coil was d*** near 1/4" from the magnet on the flywheel. Pushed the "head" of the coil much closer to the flywheel and wouldn't ya know. Got sparky!!! I first unscrewed it to see if there was an adjustment, but no possibility of adjustment



Thanks for all the help fellow riders, now to reassemble.