Jonway YY250t - 2 years later, still not running... By johnny3d (Read 14,347 times)

[johnny3d]

I do not have a ground wire going directly from the valve cover to the frame, but when I test with the multimeter (ohms), it shows that I have a good ground from the valve cover bolts to the ground on the battery. I could add a ground wire from one of the valve cover bolts to the frame.

I will try removing the kill switch wire later tonight.

When I currently engage the kill switch (OFF), I get nothing... it won't even attempt to start. When I have it in the "fun" position it will turn over as long as there is power to the battery.

This is the procedure I've tried for testing the spark:

[johnny3d]

I now have a ground wire to one of the bolts on the valve cover. Tested the spark plug against that very bolt... no spark.

The extra ignition coil I got from a 50cc... So I suppose it's possible that my original ignition coil (250cc) is bad and the 50cc ignition coil I got my hands on isn't strong enough to make any spark at all.

Both test exactly the same on the multimeter though.

I also tried bypassing the kill switch (Black and White on the two-prong connection to the CDI). I just ran a wire from the 12v DC (black) wire to the connection on the CDI to bypass. I got the same result. Started turns over, no spark.

[johnny3d]

I'm ordering a new ignition coil tomorrow.

If I keep ordering new parts eventually I'll figure out which one has been bumming me out since last fall.

[alleyoop]

DANG!! I hate a NO spark condition because it could be many things, It could be the Stator, the Pickup Coil, The Cdi, the Coil, The Boot, That is the flow for spark.
Alleyoop

[johnny3d]

Yeah. I hate it too. A lot.

I've got a spare CDI that is specifically for my scoot now. So... I can eliminate that as the problem. I'm ordering the new ignition coil tomorrow and when that gets here I'll either eliminate that from the list too or it'll fire up. If it isn't that, then I'll plan on replacing the Stator and pickup coil...

If I end up replacing all that stuff and it still doesn't want to fire up... well... I'll junk it and eventually buy a Honda Shadow or something like that. I live 20 minutes from the biggest motorcycle rally in the world (Sturgis Motorcycle Rally). There are always good deals on motorcycles around here. Though with hope I just get this thing running again.

[razzle]

Hey there, just a thought but did you check that the vacuum hose to the intake manifold didn't come undone? Seems insignificant but if you accidentally knocked it off the scoot won't start or run. Look for a hose coming off the little nipple on the intake manifold, between the carb and the engine. I believe one end goes to the carb. Hard to spot if you aren't looking. Good luck and hang in there. I have a 2008 SUNL 250 and it has been...shall we say....a learning experience.

[johnny3d]

Just got the new 250cc ignition coil in the mail... no spark.

How do I test the stator to see if it's functional? I'm so annoyed at this point.

[steve]

Set your multimeter to 20 vac and check the wire that runs from the stator pick up coil to the CDI while hitting the starter. I think mine read about 8 VAC. I believe that you can go down to the 3-5 VAC range and be OK. I'm pretty sure that you can get a replacement and it's pretty easy to get at.

[johnny3d]

Thanks for the reply on that. I'll check that tomorrow, I've had enough disappointment with this machine for today. Unfortunately the stator is the more expensive part of the bunch ($20 for the CDI, $18 for the ignition coil, and $60 for the stator). Of course, if it isn't that, then I guess I'll have to start re-wiring even though my multimeter is showing the wires as good.

[johnny3d]

Well... My multimeter only has a 10, 250, or 500 ACV setting. I set it to 10 and tested one of the yellow wires coming out of the stator which then leads to the regulator/rectifier. You can see the yellow wires in this pic:



(you can ignore the "what is this?" part because someone already told me that is the regulator/rectifier.)

When I connected to one of those yellow wires which come out of the stator, it produced about a 3-4 ACV current while turning over the engine. Honestly I'm not really sure which of the wires going into the CDI is the one that is getting the signal from the pickup coil. I re-checked the wires going from the CDI to the ignition coil with the multimeter set to 1x Ohm. That showed good connections from the CDI to leads on the brand new ignition coil.

The ignition coil has a tab that has green plastic around it and a tab with black. One of the wires that leads to the ignition coil is black with a yellow stripe and the other is green. It came originally set up with the black/yellow wire connected to the green marked tab on the ignition coil and the green wire hooked to the black tab on the ignition coil. I have tried it with the wires hooked up both ways but neither seems to produce a spark.

When testing for a spark, I have used both my old and new spark plug plugged into the ignition coil (3 of them actually) and then grounded against a valve cover bolt that I specifically attached a new ground wire to recently. It SHOULD be getting a good ground from that position, but I see no spark when turning over the engine.

So... Stator appears to be putting out voltage... I have tried the original CDI and a newly purchased CDI. I have tried 3 different Ignition Coils (original, a 50cc ignition coil, and a New 250cc ignition coil). I have tested with two different spark plugs. Both NGK plugs, one new, one old. I have checked all the connections I can find by seeing if the two sides of the connection have any OHM resistance or not. All checked out fine.

I feel like there is just going to be something stupid that I've completely overlooked. I've checked everything I can think of and everything suggested over and over and over. I smell gas on the plug after I try and turn it over a few times, so I think there is gas getting to the chamber, I'm just not getting any spark.

I so wish I could just take it into a shop. I wish a mechanic around here would fix it for me... because despite all the encouragement and suggestions, I'm not figuring it out and my scooter has now been non-functional since August 9th of last year.

[alleyoop]

Test the PICK UP COIL WIRE(TRIGGER WIRE) going into your CDI, crank it and it should read .5 to 2.5 V.
Here is the CDI and check the PICKUP WIRE(TRIGGER WIRE). Yours may not have the KILLWIRE on the two plug but the others are all standard on the CDIs. Also check the bottom wire on the TWO plug that either gets voltage from the stator or from the battery. If you check it with the KEY ON and it reads 12v then you have a DC cdi, if nothing then you have a AC CDI and it gets its power from the stator.
Alleyoop

[johnny3d]

Bottom wire on the 2-Plug gets DC voltage with the key turned to the ON position confirming a DC CDI.

Trigger wire (red/white on mine) shows a very slight AC voltage with my multimeter set to the 10 ACV setting when I crank it over. The analog meter barely moves at all, but it does move ever so slightly when I hit the starter but doesn't seem to be coming close to approaching a .5 to 2.5v.

I also tested it with it set to 10 DCV and it gave pretty much the same exact slight movement on the gauge.

I might need a better multimeter to get anything specific from that. It's a pretty inexpensive model.

[bwhitsonjr]

Did the thread get moved or did you just give up? I know I would've a long time ago.... Kudos for sticking in there I've learned a lot from all the reading! I'm glad that I don't have a spark issue. I just have a fuel issue. I can't seem to get it lined out on running rich. Although the rest of the story is when I came into posession of this same scoot you have about a month ago come to find out it doesn't have an air box. So... it will start and idle fine just doesn't run the greatest. Very rich!

[johnny3d]

No. The thread didn't get moved or anything.

I haven't completely given up yet, just mostly. I haven't bought a new Multi-Meter yet to double check the stator. Besides, if I end up having to replace the stator, I think I'd have to buy a flywheel puller tool too...

I've been trying to find a mechanic who will work on it for me at this point. Every time I go out and try to get it running and fail to get it running I just end up a bit frustrated and a little depressed about the whole thing. I'd rather find a mechanic who can diagnose the issue EXACTLY instead of just buying parts, replacing them, and it ending up not being the issue.

If I can't track down the problem soon or I can't find a mechanic, I might just sell it.

Seems like nobody even remotely close to where I live in South Dakota will even look at it to tell me what's wrong with it.

[johnny3d]

I bought a new digital multimeter. It doesn't have a 10 setting for DCV so I had to use the 20 on the dial.

Here's a picture showing the wires and how I numbered them:
(Wire #3 is hard to see, but it's the yellow black wire)




Now for the breakdown:
(with Ignition = Me pressing the starter button to try and start the engine)

1. Key On + Kill set to Fun = 0.37v, Key Off or Kill Off = 0.0v
2. Key On + Kill set to Fun = 13.05v, Key Off = 0.0v, Kill Off = 13.05v
3. Key On + Kill set to Fun = 0.0v, with Ignition = 0.3v
4. Key On + Kill Set to Fun = 0.0v, with Ignition = 0.4v to 0.22v (spiked at 0.4v then quickly dropped to 0.25v or 0.22v)
5. Key On + Kill Set to Fun = 0.36v, Key Off or Kill Off = 0.0v, with Ignition = 0.6v

I don't have a 6th wire there... so... I didn't bother testing that lead.

I'm not exactly sure what to make of those results. If you need to ask any questions for clarification, please do. I can take a pic of my multimeter if need be so you can see the setting I had it at. If there are any additional tests you need me to take to help me diagnose this, please just tell me what to test for.

Thanks again for all your help.