Here are a few things to check for and try :

1. Check the wiring

From CDI to engine :

Black to Black
Blue to Blue

From Kill switch (If one black and one yellow wire is present):

Black to Ground
Yellow to Blue to Blue Connection (CDI and Engine connection)

2. Choke

Have the choke set about halfway for starters. If it still doesn't start, move the choke lever closer to the top (off), and then start moving it lower. You will need to be at a speed of about 10-15km/hr before releasing the clutch.

3. Spark Plug
Ensure that the spark plug cap is correctly fitted to the top of the spark plug. Remove the crown (the bronze cap) at the end of spark plug to make sure it securely fits.

4. Make sure that there's enough gas in the tank. Start with a gas to oil mixture ratio of 16:1 for the first 500km of use or first 3-4 weeks. Then move to a ratio of 20:1 .

5. Check the carburator to ensure that it's been connected properly.

6. If there is still no spark, we recommend changing the spark plug. The following spark plug can be used with the motor :

NGKB5HS

7. Check the spark plug gap and that it is 0.028 - 0.034 of an inch.

8. Press the TICKLER button on the carburetor down until a little bit of gas drips out of from the air filter. Once you see some air bubbles escaping out from the carburator down the gas line into the tank, it means that it's almost ready. As soon as you see some gas drip out, take your finger off the button and dry any gas spillings with a paper towel.

* You will need to press the tickler button down before you start riding the bike if it has been over 3-5 hours since the last time you've ridden it. This will normally help the engine starting up right away.