Are you sure it's firing? What engine is fitted? If it's a chinese 'Honda' copy, the ignition coils are very prone to failure. If there is a spark, check that the choke flap fully closes when the speed control is at 'START'.
If there is no spark, you will need to replace the coil. Unfortunately this is easier said than done, since spares are unobtainable. It is possible to modify a standard (obtainable) coil to fit - drop me a line if you need one.
phil_saunders(a)bigfoot.com
Phil Saunders, April 2010
