well, im assuming that you have tried starting it up on both the electric and kick start and it still doesn't start. If the engine turns over but it won't start then it could mean that you need a new spark plug, take out the old one and see if it has any oil on it, if it has then i will advise you to kick start it without the spark plug in, that will shoot out any oil that is still inside, and clean up inside the hole and kick it again, keep doing this until no more oil comes out, put a brand new spark plug in and kick start it, as soon as it fire's up rev it very high to keep it going, and ride it around for half hour on high rev's, do this until there is no blue smoke coming out. it should be white or clear smoke coming out. when you feel that you have done it I also advise you to get a single treatment of redex and put it in your petrol tank to clear out any dirt or old oil left in you engine because I have a piaggio zip 50 and the same thing happened to me. hope this helps you.
Dan
October 2008