Kymco Super 9 won't start

[Lenkan]

Hello,
I have a Kymco Super 9 A/C from 2007 that has been mine for the last 5 years with 14000km on the odometer. It worked flawless until last week when it suddenly gave up on me, there were no special circumstances when it happened, but some slight powerloss might have been experienced some days before until the breakdown. After that it haven't fired up even once.

Things I've already tried:
Cleaning the carburator
Cleaned airfilter + everything related to the air
Checked/cleaned the reed valve membrane
(Fuel and air should not be the problem in my opinion since it wont even fire up on "starting gas spray")
Checked and replaced the spark plug
Replaced ignition coil
(I have visible sparks on the plug but it looks kinda weak)
Battery is some months old but in good condition.
Removed cylinderhead and inspected the piston, everything seems to be in good condition no scratches or cracks anywere.
(Unsure about the pistonring wear, I haven't tested the compression)

Things I'm considering:
Replace piston rings (I've got compression but is the pressure enough? What should the pressure be if I manage to test it somehow?)
Replace CDI (I'm getting sparks, but could this still be the problem? Super 9 air cooled uses the AC-CDI correct?)
Replace voltage regulator (Can a faulty voltageregulator make it unstartable?)

Or is there anything else that would help me?
Hopefully someone can help me and pardon my grammar, English is not my first language.
Best regards
Lenkan

[eamartin]

Did your scooter stop running while you were riding it? Or,  did it not start after you turned it off? 

[Lenkan]

Did your scooter stop running while you were riding it? Or,  did it not start after you turned it off?

Yes, it did stop when I was riding it.

[eamartin]

When you try repeatedly to start it, then check the spark plug, is the spark plug wet?

[Lenkan]

When you try repeatedly to start it, then check the spark plug, is the spark plug wet?

Yes the plug gets wet, the fuel delivery neither the air delivery to the cylinder seems to be the issue since it won't even start on starting gas spray.

[eamartin]

So you're getting fuel.  You have mentioned that the spark appears weak.  I suggest asking someone with knowledge to observe the spark strength.

[scooterfan]

.................................. Super 9 air cooled uses the AC-CDI correct?..............

I do not know whether your scooter has an AC or DC CDI, but I did some intensive reading about CDI's some time ago and to my understanding about from what I read I think it will make sense to find out what CDI your scooter has - AC, or DC.

If your scooter has a DC CDI, you need to understand two things:

1. The energy (Voltage) to create a spark at the spark plug comes directly from the battery.

2. The DC CDI's have capacitors - and if the capacitors do not get sufficient energy (Voltage) from the battery, the capacitors will not release sufficient energy to the ignition Coil and spark plug to generate a proper spark at the plug.
In other words - the weaker the voltage from the battery, the weaker spark you'll get at the spark plug.

Therefore I think it will make sense just to find out first what CDI your scooter has.

In case of an DC CDI:
1. Make sure that "new" battery is not faulty . (Make sure it's fully charged, and take it to a battery specialist to do a proper load test.
2. Make sure the battery terminals are not corroded, and all terminals are connected properly.

In case nobody can tell whether the CDI on your scooter is AC or DC, just take a picture of the terminals on the CDI. Also take measurements on the CDI, and forward the details.


Just another question - are you sure the valve clearance gaps on your scooter are not too small ? (The recommended gap clearances are very small, and one can easily make a mistake during valve clearance adjustments).