Jonway YY250t - 2 years later, still not running... By johnny3d (Read 14,349 times)

[alleyoop]

Let me get JR he is the ELECTRICAL GURU on these scoots actually he has 2 of the 250s I think an A and a B.
Alleyoop

[JR]

May 29, 2014 17:12:36 GMT -6 johnny3d said:

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.

#1 is kill wire, should read 0v at all times. Doesn't matter if the key is off or on, it is a ground wire. Either your meter is messing up or you have a wire touching somewhere feeding it this very small amount of current. Any voltage at all is incorrect.

#2 is 12Vdc CDI feed wire all readings are correct.

#3 is feed wire from CDI to coil, very hard to read this at all and I presume when you say with ignition you mean turning the engine over? A ordinary meter isn't fast enough to get any accurate readings on this wire, I would say the reading is incorrect but again you can't read this wire.

#4 is the ground should have 0v on all functions, grounds have no voltage, if you do have current then you've got either a hot wire crossed on it or even a possible bad ignition switch or even a incorrect CDI. Do you know for a fact you bought a DC type CDI? If you put a AC type on then it'll never run.

#5 is pulse coil (trigger) wire from the stator. With the engine turning over it should as others stated read between .5 to 2.5 Vac.

Pull the plugs out of the CDI and test each wire again like this:

#1 Set your meter to the ohms scale reading, touch both probes to each other and take note of the reading on your meter. Then with the engine kill switch in the run position, put one lead to the black/white wire, the other to the negative post of the battery, you should get no movement or ohms resistance on your meter. Then with the meter still hooked up put the kill switch in the off (engine kill) position and then take note of the reading, it should read nearly the same as when you touched the two meter leads together to start with, if not then we have a problem.

#2 is fine, it's the DC feed to the CDI with the key on, you've already confirmed this.

#3 should read 0v, nothing.

#4 is again a ground, put one lead to the negative post of the battery and the other to this green wire, it should read just like when you put the two meter lead wires together full resistance

. #5 is pulse coil feed wire, should read 0v with scooter not running. Should read from .05 to 2.5Vac with engine being turned over.

JR

[johnny3d]

May 29, 2014 19:54:08 GMT -6 JR said:

#1 is kill wire, should read 0v at all times. Doesn't matter if the key is off or on, it is a ground wire. Either your meter is messing up or you have a wire touching somewhere feeding it this very small amount of current. Any voltage at all is incorrect.

#2 is 12Vdc CDI feed wire all readings are correct.

#3 is feed wire from CDI to coil, very hard to read this at all and I presume when you say with ignition you mean turning the engine over? A ordinary meter isn't fast enough to get any accurate readings on this wire, I would say the reading is incorrect but again you can't read this wire.

#4 is the ground should have 0v on all functions, grounds have no voltage, if you do have current then you've got either a hot wire crossed on it or even a possible bad ignition switch or even a incorrect CDI. Do you know for a fact you bought a DC type CDI? If you put a AC type on then it'll never run.

#5 is pulse coil (trigger) wire from the stator. With the engine turning over it should as others stated read between .5 to 2.5 Vac.

Pull the plugs out of the CDI and test each wire again like this:

#1 Set your meter to the ohms scale reading, touch both probes to each other and take note of the reading on your meter. Then with the engine kill switch in the run position, put one lead to the black/white wire, the other to the negative post of the battery, you should get no movement or ohms resistance on your meter. Then with the meter still hooked up put the kill switch in the off (engine kill) position and then take note of the reading, it should read nearly the same as when you touched the two meter leads together to start with, if not then we have a problem.

#2 is fine, it's the DC feed to the CDI with the key on, you've already confirmed this.

#3 should read 0v, nothing.

#4 is again a ground, put one lead to the negative post of the battery and the other to this green wire, it should read just like when you put the two meter lead wires together full resistance

. #5 is pulse coil feed wire, should read 0v with scooter not running. Should read from .05 to 2.5Vac with engine being turned over.

JR

Okay... First, I took a pic of my multimeter so it's clear what I mean when I talk about the settings I used to do the tests:




Going down your list here are my results:

#1 (Black and White): With the multimeter set to 2000 Ohms, touching the two probes together would result with 000. With the kill switch in the "Run" position, I got no reading at all. With the kill switch in the "kill" (or off) position I get 164. I re-tested at 20k Ohms and got 000 with just the probes, no reading with the kill switch in the "Run" position, and .57 in the "Kill/Off" position.

#2 (Black) Re tested just to be sure... getting 13.02 vDC on the 20 vDC setting on the multimeter.

#3 (Black and Yellow): With the multimeter set to the 20 vDC  setting, I get 0 vDC. I did notice that if I switched it to to the 200m vDC setting, I was picking up a reading of 11.2.

#4 (Green): With the multimeter set to 200 ohms, I get .2 on the probes alone, and 6.6 on the green wire. On the 2000 ohms setting I get 000 on the probes and 000 on the green wire. Even with it disconnected from the CDI, when turning the engine over it does read .2 vDC. 

#5 (Red and White): I set the multimeter to 200 vAC and while turning over the engine I got 0v. When I let go of the ignition and stop turning over the engine it would jump to .6 vAC or 1.5 vAC or .9 vAC. But whenever I was actually turning the engine over, I got no reading on the vAC.

That was all tested with the plugs disconnected from the CDI. I dug up the order for the new CDI that is in there and it is listed as: "6-Pin DC-CDI Box for 250cc Scooters & Go Karts", so unless they sent me the wrong one, it's a DC CDI.

[steve]

I would look at the coil first on Alleys list. I've had to toss several of these because it would seem that the Chinese haven't figured out how to install the connector/boot on the sparkplug end. There is a very good chance that your problem lies there.

[JR]

May 30, 2014 2:15:54 GMT -6 johnny3d said:

May 29, 2014 19:54:08 GMT -6 JR said:

#1 is kill wire, should read 0v at all times. Doesn't matter if the key is off or on, it is a ground wire. Either your meter is messing up or you have a wire touching somewhere feeding it this very small amount of current. Any voltage at all is incorrect.

#2 is 12Vdc CDI feed wire all readings are correct.

#3 is feed wire from CDI to coil, very hard to read this at all and I presume when you say with ignition you mean turning the engine over? A ordinary meter isn't fast enough to get any accurate readings on this wire, I would say the reading is incorrect but again you can't read this wire.

#4 is the ground should have 0v on all functions, grounds have no voltage, if you do have current then you've got either a hot wire crossed on it or even a possible bad ignition switch or even a incorrect CDI. Do you know for a fact you bought a DC type CDI? If you put a AC type on then it'll never run.

#5 is pulse coil (trigger) wire from the stator. With the engine turning over it should as others stated read between .5 to 2.5 Vac.

Pull the plugs out of the CDI and test each wire again like this:

#1 Set your meter to the ohms scale reading, touch both probes to each other and take note of the reading on your meter. Then with the engine kill switch in the run position, put one lead to the black/white wire, the other to the negative post of the battery, you should get no movement or ohms resistance on your meter. Then with the meter still hooked up put the kill switch in the off (engine kill) position and then take note of the reading, it should read nearly the same as when you touched the two meter leads together to start with, if not then we have a problem.

#2 is fine, it's the DC feed to the CDI with the key on, you've already confirmed this.

#3 should read 0v, nothing.

#4 is again a ground, put one lead to the negative post of the battery and the other to this green wire, it should read just like when you put the two meter lead wires together full resistance

. #5 is pulse coil feed wire, should read 0v with scooter not running. Should read from .05 to 2.5Vac with engine being turned over.

JR

Okay... First, I took a pic of my multimeter so it's clear what I mean when I talk about the settings I used to do the tests:




Going down your list here are my results:

#1 (Black and White): With the multimeter set to 2000 Ohms, touching the two probes together would result with 000. With the kill switch in the "Run" position, I got no reading at all. With the kill switch in the "kill" (or off) position I get 164. I re-tested at 20k Ohms and got 000 with just the probes, no reading with the kill switch in the "Run" position, and .57 in the "Kill/Off" position.

#2 (Black) Re tested just to be sure... getting 13.02 vDC on the 20 vDC setting on the multimeter.

#3 (Black and Yellow): With the multimeter set to the 20 vDC  setting, I get 0 vDC. I did notice that if I switched it to to the 200m vDC setting, I was picking up a reading of 11.2.

#4 (Green): With the multimeter set to 200 ohms, I get .2 on the probes alone, and 6.6 on the green wire. On the 2000 ohms setting I get 000 on the probes and 000 on the green wire. Even with it disconnected from the CDI, when turning the engine over it does read .2 vDC. 

#5 (Red and White): I set the multimeter to 200 vAC and while turning over the engine I got 0v. When I let go of the ignition and stop turning over the engine it would jump to .6 vAC or 1.5 vAC or .9 vAC. But whenever I was actually turning the engine over, I got no reading on the vAC.

That was all tested with the plugs disconnected from the CDI. I dug up the order for the new CDI that is in there and it is listed as: "6-Pin DC-CDI Box for 250cc Scooters & Go Karts", so unless they sent me the wrong one, it's a DC CDI.

OK Johnny let's start over, I went back to the first page looked at your video and saw you have the vertical engine. I have the horizontal linhai and they both use the same CDI and this is confusing but they both have 18 coil stators, the coil is the same but on your vertical engine the stator is a little smaller even though it is 18 coils.

Now the Chinese use two different wiring systems as far as how they kill the engine and use the kill switch on the handle bars and what's even more confusing is they may wire your scooter and a linhai the same or they may have them a little different, you don't know until you test, very confusing and a PITA.

So with that in mind I need you to test this system again to let me know which you have. Also on the ohm testing use the 20k setting only. I have opened up my linhai to test using the same meter set up that you have, readings may vary, but very little. Also I do not want you to do any DC voltage tests, we know the ignition key wire (black) # 2 has the proper DC voltage so that wire is OK and doesn't need to be checked again.

#1 The black/white wire put one probe to the negative post of the battery the other to this wire. Turn the key on. Make sure the handle bar kill switch is in the run position.  Your meter in the 20k spot should simply have one number on it and that's a 1. Now with the probes still hooked up turn the key off, the meter should read 0.00.

Now turn the key back on and with the probes still hooked up turn the kill switch to off, take note if the meter changes readings. If it goes to 0.00 or if the meter does nothing it will tell me your wiring configuration.

#2 Black is 12Vdc is ok so move to 3.

#3 yellow/black = coil feed wire. Again on the 20k setting with key on or off doesn't matter you should read 0.00 or very close, may even be a -0.02 or -0.03 but this wire should have no reading to ground, it is a voltage feed wire from the CDI. If you have a high or significant reading it could indicate a bad coil or the coil feed wire is grounding out. Again test for ohms only at 20k

#4 green = ground again with one probe to the negative battery post and the other to this green wire turn the key off and the kill switch to the run position. If you have the system I think you do the meter should read 0.00. Now with the probes still hooked up put the kill switch in the engine kill position. If this is the system I think then the meter will go back to 1. If the meter does not change at all with the kill switch in run or kill then  I know the CDI is grounded out via the black/white wire that you are testing as #1.

#5 Your test is confusing so let's do it again. Put meter on 200Vac only. With key on and engine kill switch in run position turn the engine over. The readings will jump because remember this is a coil that makes a very weak voltage signal to send a message to the CDI as to when to fire. It has one magnet that is on the flywheel that passes by the coil once every revolution so it's common for the readings to vary and go up and down.

Your coil wire readings concern me and I'm leaning to a bad/weak coil.

JR

[johnny3d]

More results:

Test #1 (Black & White): With the Key ON and kill in RUN position I got the "1" on the meter. Turning the key OFF and it did change to 0.00. Key back to ON with the kill in OFF the meter changed to 0.56

#2 skipped (good to go here)

Test #3 (Yellow & Black): Key OFF = 0.00, Key ON = 0.45

Test #4 (Green): The meter read 0.00 and does NOT change regardless of kill switch position.

Test #5 (Red & White): When turning the engine over I get .2 at the beginning, then it drops to 0.00 as the engine continues to crank. Then when I release the ignition it jumps 1.6... Repeated that a few times and got the same result (with slight variation to the jump at the end after releasing the ignition button) each time.

[JR]

#1 is a good check this tells me that the kill wire is working correctly on the key switch and on the kill switch. Even though the reading with the kill switch is 0.56 that could be a slightly corroded kill switch but still is good enough to kill the engine when using it. This also tells me what configuration you have and that the kill wire is not grounding out the CDI in any way.

#2 is good

#3 is good.

# 4 is good and telling us the CDI is properly grounded

#5 again a hard one to read with a multi-meter but your results are exactly as mine are and my scooter is running.

So now what is going on? Good question. Just because the coil wire read correctly doesn't mean the coil is good? We have eliminated wiring and voltage possibilities except the yellow black wire going to the coil needs to be checked where it plugs into the CDI and hooks up to the coil. The ground wire to the coils need to be checked as well. Also check the plug boot and make sure it's all in good shape and making contact to the spark plug well. Should all of this check out then I would lean towards a new coil.

There is also the possibility that you bought a bad CDI? It happens.

JR

[johnny3d]

All tests at 20k Ohms:

Green Wire to Battery ground = 0.00
Black/Yellow to CDI Plug Black/Yellow = 0.00

I have two 250cc ignition coils:

#1 (new): Green tab to boot = 6.85, Black tab to boot = 6.85
#2 (old): Green tab to boot = 7.75, Black tab to boot = 7.75

Boots on both are in good shape. It FEELS like both of them make good contact to the spark plug. I hear an audible "click" sound when they are firmly seated on the spark plug.

I decided to do a few other tests.

Using the 20k Ohms setting:
NGK DR8EIX:
I got a 5.05 from connection tip to spark end on the spark plug alone.
When plugged into the New Ignition coil boot (the one with the 6.85 Ohm reading), I get 11.88 from either tab on the ignition coil to the tip of the plug. I also get 11.88 from the Green Wire and Black/Yellow wire on the CDI plug to the tip of the plug. So... as near as I can tell, I am definitely getting a good connection all the way from the CDI plug to the tip of the spark plug.

I also took my old spark plug which had been sitting out of the engine for a long while now and smelled it. It didn't smell like much of anything. I put it in the engine and turned it over a few times. Then I took the plug out of the engine and it smelled of gasoline. So I assume that gas IS making its way there.

With the spark plug plugged into the boot of the ignition coil (and the ignition coil hooked up to the CDI and everything), I placed the flat metal part of the spark plug against the ground on the battery and turned the engine over to check for spark... I saw no spark being produced at all.

It is possible that my old CDI and my new CDI are both no good. It SEEMS like from my tests that my ignition coils are probably both good. I know the connection from CDI to the tip of the plug is fine since I tested that... or seems that way.

[JR]

This is always a possibility when buying Chinese parts. Good test on the turning it over and then checking the plug. You are getting gas.

So we have confirmed good wiring, getting gas, getting voltage to the CDI, good ground to CDI and kill wire working correctly. Down to two things, bad CDI or bad pulse coil, which I don't believe is the case.

You could do this simple test to just confirm our kill wire readings. Take a tiny screwdriver or bend the end of a paper clip and insert it in the tiny slot at the end of the CDI plug with the black/white wire and bend the locking tang and pull this wire from the plug. Then see if you have a spark? If not then bend the locking tang back out and re-insert the wire into the plug.

Next option is to get another CDI and I would order from one of our vendors here, tvnacman. He tests and stands behind his parts.

JR

[johnny3d]

I am having trouble finding a DC CDI for a 250cc with the square plug like mine on tvnacman's site. I'll try disconnecting the kill switch wire later, but I wanted to see if I could find that CDI on there. I like the idea of it being a tested/known good part. I found an AC one that looks like mine, but not a DC one.

[alleyoop]

Is this it?
Alleyoop

.ebay.com/itm/6-Pin-DC-CDI-Box-250cc-Scooter-Moped-Go-Karts-Dune-Buggy-Cart-/170902744260" rel="nofollow" target="_blank">.ebay.com/itm/6-Pin-DC-CDI-Box-250cc-Scooter-Moped-Go-Karts-Dune-Buggy-Cart-/170902744260

[johnny3d]

May 30, 2014 21:48:26 GMT -6 alleyoop said:

Is this it?
Alleyoop

.ebay.com/itm/6-Pin-DC-CDI-Box-250cc-Scooter-Moped-Go-Karts-Dune-Buggy-Cart-/170902744260" rel="nofollow" target="_blank">.ebay.com/itm/6-Pin-DC-CDI-Box-250cc-Scooter-Moped-Go-Karts-Dune-Buggy-Cart-/170902744260

Yeah. That one looks just like the one I bought before and even has the pretty much the same description. I was trying to find one on Tvnacman's site because those are all tested/known good parts. Where as the previous one I bought from "PowerSportsMax.com" may not be functioning.

[alleyoop]

Here are the CDIs, on Johns website
Alleyoop

.testedscooterparts.com/product_info.php?products_id=10566929" rel="nofollow" target="_blank">.testedscooterparts.com/product_info.php?products_id=10566929

[JR]

I'll send John a email.

JR

[johnny3d]

I'm planning on ordering the new CDI from John's site. I put it off for a long while because my in-laws filled my garage with crap and I couldn't really work on the scooter. Additionally, I just got so frustrated with trying things and having them not work that I kind of lost hope on it. They even unplugged my battery tender, so there is a chance that my battery is hosed since it hasn't had a charge in it for about a year.

I'll let you guys know when I get the new CDI and see if that works. I would REALLY like to get my scooter up and running again.