Hi,
You have spark but is the fuel getting to the cylinder (is the plug wet with fuel when you remove it after trying to start). Look at the vaccum fuel supply valve if the fuel isn't getting through. Also don't twist the throttle as you try to start the engine as you will flood the cylinder (let the choke do the work.
Chinese four strokes are notorious for the tappet gaps closing after some use (poor pre delivery checks), check the gaps are correct as this will prevent the engine starting.
Lastly, the spark should be a nice blue colour, if it's not check the engine and battery earth straps.
Cheers
westcountry, October 2013
