scooter sputtered this morning and then died.

[scooterfan]

Okay, you have an electrical problem.
This is what I would do:
 1.  Have a close look at the fuse connections. The connections or fuses could be corroded, or the the fuses could be sitting slightly loose inside the connections.
2. Do a resistance test on the spark plug cable to see if the wire is not broken.
3. Make sure the spark plug Cap is properly connected to the cable, and make sure the other end of the cable is properly connected to the Coil.
4. Hook the Battery to a Battery Charger, and make sure the battery is fully charged.
    You mentioned the battery is new - but that does not mean the battery is fully charged or the battery is not faulty. Hardly any battery that comes off a shelve is fully charged - you actually need to hook it to a charger to get it fully charged.
This is very important on our scooters with DC CDI's - the CDI's on our scooters need an almost fully charged battery to generate a proper spark at the Spark Plug. It is important to understand that on our scooters with DC CDI's the Battery itself actually generates the spark at the Spark Plug (Capacitors at the inside of the CDI as well as the Coil just boost power to give a powerful spark at the Spark Plug).

So the weaker the Voltage at the Battery - the weaker the spark at the spark plug will be.
Apart from charging the battery, the Stator on our scooters only triggers the CDI to release power to the Spark Plug.

If the battery is fully charged and the scooter still does not start, you can do the following:

1. Unplug the 2 pin plug at the CDI.
  The two pin plug only has one wire - the thin wire on that plug actually feeds power from the Battery to the Spark Plug (via the Capacitors in the CDI, the coil, and spark plug Cable).
So while the two pin plug has been unplugged, you need to do a Voltage test at the single wire on the loose plug.
With Ignition Switch in "on" position and the Negative wire on the Multi meter linked to (-) on the Battery, you should get between 12 -13 Volt reading at the connection on the plug. (The same Voltage reading when you do a direct Voltage test on the Battery).

Then
With the two pin plug still unplugged, somebody need to press the Starter Button to swing the engine.
While the engine is swinging, you need to do a Voltage Test at the single wire on the loose plug.
You need to get a voltage reading of at least 9.65 Volts on the loose wire - otherwise you will get an improper spark at the Spark Plug, and therefore starting problems.

If the Battery was fully charged but the Voltage at the loose wire on the plug was lower than 9.6 Volts, it means you have a voltage drop in the power line elsewhere before the Plug, or the new battery might be faulty.
New batteries are not faulty that often - but in our country it happens fairly often.

You should get a proper load test done on the battery before you buy another battery.

If everything looks okay and the scooter still does not start - you could try a new Voltage Regulator.
I do not know how it actually works, but some time ago somebody on a forum elsewhere mentioned that a starting problem on his scooter was solved by replacing the Voltage Regulator.
Not so long ago somebody on this forum also could not solve a starting problem - I just can't remember his name or scooter model.
 I mentioned the guy who solved his problem with a Voltage Regulator, the guy on this forum installed a new Voltage Regulator - and his problem was solved.

I hope this helps.

[aschrauth]

update on progress as of 11/4/2020

So I ordered this CDI from amazon and it arrived today in the mail.

WFLNHB Ignition Coil + DC CDI Fit for Kymco, SYM, Vento Scooter GY6 Engine Parts

Installed it and tried to check for Spark when all of the sudden I herd a popping sound coming from the CDI, Stopped immitiantly and found that the CDI was Hot to the touch. This CDI upon further inspection looked similar to an AC one. My guess is the seller on amazon is selling counterfeit CDI's that are marketed for DC scooters.

Defiantly will be returning this POJ. Bit the bullet and ordered a New OEM Kymco CDI as well as A preformance CDI like the one I had before. If you see this product anywhere make sure to avoid purchasing it.

[scooterfan]

I could be wrong but I think something else is causing your CDI problems. Maybe you should remove the Voltage Regulator , have a close look at it and do a test on it with a Multimeter. There are Youtube videos which shows how it can be tested.

[aschrauth]

Ok everyone an update on my progress as of 11/6/2020

So the new Cdi came in the mail today, I installed it and it fired right up. I have an OEM Kymco CDI coming in the mail next week just in case the one I got from Amazon checks out. while I was in the engine area I also removed the PAIR system and blocked off the hole on the Head. I was told this is for emissions ( My state doesn't do emissions on motorcycles). As of now the Bike is running like it originally did. Not really sure what happened with the old CDI but I am going to do the test that @scooterfan recommended. One thing I did notice was that the engine ran better with the PAIR system off, not sure if I will gain performance but It sure did free up a bunch of hoses and pipes.

[scooterfan]

update on progress as of 11/4/2020

So I ordered this CDI from amazon and it arrived today in the mail.

WFLNHB Ignition Coil + DC CDI Fit for Kymco, SYM, Vento Scooter GY6 Engine Parts

Installed it and tried to check for Spark when all of the sudden I herd a popping sound coming from the CDI, Stopped immitiantly and found that the CDI was Hot to the touch. This CDI upon further inspection looked similar to an AC one. My guess is the seller on amazon is selling counterfeit CDI's that are marketed for DC scooters.

Defiantly will be returning this POJ. Bit the bullet and ordered a New OEM Kymco CDI as well as A preformance CDI like the one I had before. If you see this product anywhere make sure to avoid purchasing it.

I forgot to mention - the AC CDI’s are smaller than DC CDI’s.  If that was an AC CDI chances are about  Zero that the engine would start.

In your latest post you mentioned that you got the engine running with another CDI again.
Maybe you should just do an ordinary Voltage test at the battery at idling and then at higher engine speed as well.
I think there is a possibility that a CDI can get cooked if the Voltage output is too high at the Voltage Regulator.

[aschrauth]

OK everyone heres an update on my progress as of 11/8/20

So I found out that I have a leaking fuel shutoff valve that is attached to the gas tank, I tried to tighten it but for some reason it is leaking where the stem strainer meets the valve, So I plan on ordering a new one.

Issue 2, Ever since I removed the PAIR system My valves are making a noticeable audible " Ticking sound". I reattached the PAIR system an In addition I also found out in the service manual for the kymco 125 that both valves are suppose to be set at 00.12mm. Before I had them set at 0.04 for intake and 0.05 for the exhaust. 0.04 and 0.05 were set stock from the factory. Im confused as to which one to set the valves to. Other than that the scooter runs perfect. When the valves are adjusted at 0.04 and 0.05 there is still an audible ticking but it is not as loud. Currently I have both intake and exhaust set at the service manual recommendations.



Went for a ride today to Work which is approximately four miles to and from  and everything on the scooter seemed OK besides a small drip from the fuel petcock. Going to attempt to ride to work tomorrow, Praying that nothing goes wrong.

scooterfan suggested that I take a look at the voltage at Idle and the voltage at WOT, This could be the issue with why the bike keeps burning through CDI's. I have a spare voltage resistor laying around and will probably install it next week. Did not have the time to test today due to limited daylight.

Below is the audible ticking sound that is coming from the valves, For some reason It will not let my upload it to this forum but I will upload it VIA YouTube.

[scooterfan]

The PAIR system on my Agility is still in place so I do not know what the valve noise would be like when the system gets removed. Valve clearance gaps on my Agility always get set at .12 mm.
At almost 26 000km the engine still runs perfectly.

P.S. Regarding CDI’s - I think the best investment a scooter owner can ever do on a scooter is to buy a proper Multimeter. There are plenty Yotube videos available to show how different scooter components can be tested with a Multimeter.
I am not sure whether you have one - therefore my comments.

[Iahawk]

I think a common area of confusion is the valve clearance....004 or .005 INCHES or .12 MM.   The inches and mm get mixed up. Looking at the conversion calculator .12 mm = .0047 inches.

[scooterfan]

I assume this scooter’s problem has been solved ?

[aschrauth]

I assume this scooter’s problem has been solved ?

Yes, So far so good, replaced the regulator rectifier and everything seems ok. I do have another issue that I really didnt realise untill I put on my new carb. At 1/4 throttle I noticed that the engine  RPM is higher. In Missouri it is getting cold ( low tonight is 25) would upgrading to a larger jet size allow more fuel to flow. I know in the cold that engines neee more fuel to run, would increasing the jet size bring down the rpm at 1\4 throttle?

[ricoswave]

I had the exact same problem and did the exact same diagnosis.  Problem is the clearance on the valves mentioned elsewhere in the valve adjustment section of this kymco 125 section blog.  Kymco says .004mm.  Should be .004INCHES or .012mm.  I have a kymco manual that shows both specs!  Shame on Kymco.  After adjusting, my headaches disappeared!!!  Good luck!

[ricoswave]

Sorry, all this diagnostic stuff has made me crazy.  .12mm is the correct measurement which is about .0047 inches.  Basic point is if you set the valve clearances up for .004mm like the Kymco manual says in the valve clearance adjustment section, the scooter will die once it warms up and the parts expand.  Talking about the agility 125 here.  Good luck!