problem with spark  By  jalat (Read 3,972 times)

Good analysis, Jalat, but I don't think the pulse generator is adjustable. It sounds like you might be losing the DC input to the CDI. As a quick check, I would try jumping 12 volts off the battery directly to the black/grey or black (DC input) wire connector at the CDI and then try starting. If it keeps running, then this will be the problem. Checking the DC feed circuit to the CDI would be the next step.

Thank you cruiser and JR.

This broken jonway is euro version too like mine. They are without diode and driving lights can be on without engine running.

I forgot to mention that we also tested kill switch on right handlebar and also tested kill switch from the side stand. Both were ok. And if there would be problem with any of those two kill switch then there would be no spark at all. I tested it with my own fully workin jonway yy250t.

We also tried it with my spare cdi-box and it acted a little different with it.

With origina cdi-box there was spark:
- when ignition key is ON (just one spark)
- when you pull break lever to turn on breaklight for starting (one spark)
- when crank one time or many timens (just one spark at first time)
- then no spark what ever you do before you turn ignition key off and back on.

With my spare cdi-box it gives spark a little different
- turn on key (one spark)
- pull break lever (one spark)
- hit start button one or many timen (couple of sparks every timen at the beginning when I push the start button)
- but if i crank over than 1 second it stops sparking until ignition key is set off and back on

Really weird thing.
We tested both cdi-boxes with my jonway yy250t (euro version also) and my jonway started and gave revs with both cdi. So I don't believe the problem is with cdi-box.

Four wires going to ignition switch were
- red (constant +12v)
- red/white (where 12v return when key is turned ON)
- black (if i remember right this was going to R/R)
- green (so it makes this ground)

But there was also two seapare wires at the front of the scooter. Green wire with male bullet type connector and black wire with female bullet type connector. Both wires are located near the ignition key wiring connector. At the beginning that green wire was connected with black wire and that did break the main fuse when ignition key was turned on. We checked every damn connector in the whole scooter. Cleaned every connector and of course this one connection was the last contact we separated Then fuse did not broke anymore.

With multimeter we measured that green was ground.
And that black wire was goin to the R/R black wire.
But black wire in ignition key connector also went to the same black wire in R/R.

We separated those wires and now we don't know where they should be connected. There is no other wires there at the front where they could go. Or should they be connected anywhere at all?
I don't know. These two wire are a big mystery.

Getting messy the whole thing. But good thing is that we have a lot of spare parts and we have fully working jonway yy250t right next to it so we can test different parts that are they working at all.


This jonway yy250t (euro version) wiring diagram that I found while ago shows that there should go only 3 + 1 wires to the cdi-box. But in this scooter and in my scooter there goes 3+2 wires.
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But in this other wiring diagram there is 3+2 wires also in cdi-box.
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I'm not sure where all these wires go from cdi-box and how to measure them with multimeter and measure against what? And what should be the values with multimeter.

I guess I also have to check with magnet that is the cdi-box DC or AC box.

Since you have a duplicate scoot that is working I would PLAY follow the leader, check the wireing that you believe is wrong with the good one.
Alleyoop

Thousand thanks already. We start digging this scooter

Problem solved.
Last owner was connected two similar looking two wire connectors wrong. Wires were near cdi-box.
Another connector was the one which goes to auto choke.

We re-connected those wires as they should be and problem was gone. Nice clean spark and motor is running.
Now it needs a little adjusting or something, because it is bugging when we give a good revs. Maybe bad cdi-box or hole in carb diaphragm.

But this spark problem is now solved.
Thank you JR, cruiser and alleyoop