Please confirm me if your engine is a 2 stroke or 4 stroke , i do face the same problem the results is easy , if there is no fire , check your coil in the magneto if it feed elecric current to your CDI , if the coil good , so therefore its your CDI which is not good, while a riding a distance its overheat it stops to feed electric to ignition coil to supply fire to sparkplug which is very poor or even not start. so change the CDI to a new one that feed full fire in the sparkplug and it will start easily that will solve the start problems
Mr. Toofany, of Mauritius, email : omnift@intnet.mu, July 2008