Possible ignition or fuel problem?

[NC3x58]

I have a 2009 Agility 125 with right around 2000 km, and use it as my pit bike at the drag strip mainly. I had bought it at the beginning of 2018 with around 1700-1800 km on it and it ran beautifully for the first 2 months of the race season. One day at the track it decided to not start after already being ridden half of the day, and I went through and checked if it had compression, fuel and spark. Compression was fine, i cleaned the carb and what finally did the trick was replacing the spark plug. After that it rode fine again for a couple weeks and randomly wouldn't start one morning, so I replaced the spark plug again and it ran at my house, so I rode it down the driveway and back again and it just quit. I replaced the coil/wire, cleaned the carb again and even checked and adjusted the valves but nothing worked. So I let it sit for 2 months for the rest of my racing season (season goes from April to October roughly) and I had went out to put it away for winter and it started without zero issues and warmed right up... What could cause behavior like this and what should I replace next so it will be reliable at the race track for me? I'm wondering if anyone else has had experience with any of this, a couple things I'm thinking next is to replace the cdi and/or the auto choke? I'd like to keep cost down and not replace both though.

[scooterfan]

Sounds like your CDI is dying. I experienced more or less the same problem, and the problem was solved by replacing the CDI.
Right or wrong, I actually started wondering whether these CDI’s can really handle high engine RPM’s at higher speed. My original CDI started dying just after a couple of faster rides on the open road.

Whatever the case, I bought a spare CDI just in case...

[NC3x58]

Okay, I'll start there then.. Where would be the best place to order one? I ordered the coil off of the ruck shop I believe.

[scooterfan]

Okay, I'll start there then.. Where would be the best place to order one? I ordered the coil off of the ruck shop I believe.

Hopefully somebody else might be able to give advice. I am from South Africa and got hold of aftermarket CDI’ from a local Chinese scooter dealer. Unfortunately the dealer did not supply a part number.

I think you actually need to forward a photo of your scooter’s CDI. According to a photo elsewhere these models came with different CDI’s.

[jeeves]

Does sound like a bad CDI.
Buy a cheap replacement if you can try it before buying it.
I ended up buying a second hand CDI because the aftermarket one for some reason didn't work.

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[NC3x58]

I went ahead and ordered two from The Ruck Shop, hopefully be here friday and I'll put it in sometime soon and see how it acts.

[NC3x58]

Will a normal GY6 CDI work on the Kymco Agility 125? I put it in and went to turn over the motor and it blew one of my fuses... Changed the fuse and put original CDI back in and it turned over and actually started and warmed up in 40 degrees Fahrenheit surprisingly..

[jeeves]

Will a normal GY6 CDI work on the Kymco Agility 125? I put it in and went to turn over the motor and it blew one of my fuses... Changed the fuse and put original CDI back in and it turned over and actually started and warmed up in 40 degrees Fahrenheit surprisingly..

From my experience GY6 electronics will not work on Kymco.

Had to change my regulator/rectifier and bought an aftermarket GY6 one. The seller had Agility City 125 on their compatible scooter list, but it didn't work.
Had to buy original Kymco.

Same thing with the CDI.



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[scooterfan]

Will a normal GY6 CDI work on the Kymco Agility 125? I put it in and went to turn over the motor and it blew one of my fuses... Changed the fuse and put original CDI back in and it turned over and actually started and warmed up in 40 degrees Fahrenheit surprisingly..

No not all of them work - I ordered one which looked the same (on a picture) as my faulty one from China but on arrival I discovered that the ordered plug was a lot smaller than the original CDI. When I plugged the CDI in it instantly blew one of the fuses.

I did some reading regarding CDI's and discovered that the smaller type CDI's  (like the one I ordered) are always AC  CDI's
The bigger type CDI's (like the OEM CDI's on our scooters) are always DC CDI's.

So if you are thinking of trying an aftermarket CDI, just be aware of the fact that the small CDI's are "AC" CDI's , and there is no chance that it will work.

[NC3x58]

Okay, that makes perfect sense now.. The two I bought are the smaller ones, I'll have to see where I can get the bigger type one. Does it matter if it says its for 50cc or 125cc?

[scooterfan]

Okay, that makes perfect sense now.. The two I bought are the smaller ones, I'll have to see where I can get the bigger type one. Does it matter if it says its for 50cc or 125cc?

According to several eBay ads some CDI's are suitable for 50cc, 125cc, and 150cc models. I think if you place an order it would make sense to have a look at year model as well.
 Another forum member placed a picture of a CDI from his scooter - the year model of our scooters are the same, but the color of the plugs on the CDI's are different. I am not sure whether plug color is important.

Something else is important - when I was looking for an aftermarket CDI, a local dealer pointed at the slight "gap" between my faulty OEM CdI's body, and the (white) plug connected to the CDI. The dealer showed me the only CDI he had in stock - the CDI didn't have a gap between the body and the plug, and the dealer told me that CDI would not work on my scooter.
I eventually found a CDI with the gap at another dealer who sells cheaper Chinese scooters, and bought a second CDI as a spare.
Unfortunately the CDI's come without part numbers and the supplier didn't give me any details. I got the feeling they tried to keep closer details for themselves.

[NC3x58]

Okay, I think I found the correct CDI from a reliable source here in the states.. I hope that helps, plus I ordered a new Automatic Choke just because it sounded like it wasn't working correctly when I started it on Sunday so that could have been a small part of the problem.. It is 10 years old by now, so it doesn't surprise me... While I have the carb off, I'll give it a quick clean and make sure I seal it back up real good and hopefully this thing will be ready to go for me all season

[scooterfan]

Hi NC3x58, I did some reading about CDI's and discovered someinfo which are quite important.

Scooters with 12 Volt batteries (like ours) come with 12 Volt DC CDI's, and the DC CDI's need 12 Volt power supply from a FULLY CHARGED battery to work properly.

This confirms what Trucker jay and Crossbolt also mentioned elsewhere - they just installed new batteries when they experienced hard start problems, and the problems were solved.

If I were you I would do a voltage test on your scooters CDI to see what Voltage reading you get. I just did a Voltage test my scooter's CDI plug, and you can just follow these steps:

1. Unplug the 2 pin plug on the CDI.
2. You will see the 2 pin loom has only one wire connected to the plug. That wire is the power supply from the Ignition Switch to the CDI, and you need to do a Volt test on the loose plug to see what Voltage reading you get.
3. Then just switch the Ignition Switch in the "On" position, earth the Volt meter to the battery's Negative (-) terminal , and do the Volt test on the loose terminal.
4. You need to get at least a 12 Volt reading - otherwise even a brand new CDI in perfect condition might not work properly.

[NC3x58]

Okay cool, I will definitely check that out then!! I'm hoping that isn't the case because I try to keep the battery on a trickle charger when not in use, but I will check that. If that is the issue, I'll keep the new one I ordered because having spare parts around IMO is never a bad thing.

[scooterfan]

Okay cool, I will definitely check that out then!! I'm hoping that isn't the case because I try to keep the battery on a trickle charger when not in use, but I will check that. If that is the issue, I'll keep the new one I ordered because having spare parts around IMO is never a bad thing.

I think you should also ask somebody to press the starter button when you do the Volt test on the plug.
When I did the test a bit earlier today I didn't have assistance to press the starter button.

Pressing the starter button will not cause any problems- the engine will just not start because there will be no power supply at the CDI.