Dont feel to bad about it. its just something that has always been done. Its just one of those things that has been standard yah know? just remember that there is no such thing as a 80cc happy time and that they are all 66cc and you'll be golden. also, Flying horse engines IMHO are great. have never had a problem with mine (took proper precautions and swapped mounting studs along with a few others.. total upgrade cost 14$)
Cheers SS