Originally Posted by jji7skyline
Most kits are the same (similar), except very rare cases. For example Rocksolidengines in australia who rebuild their engines and replace with quality bolts and stuff before selling them. I don't know of any vendor in USA that does this. Other than these kits, and the branded kits which concentrate more on performance than quality, most engines are same (similar).
Arrow Motorized Cycles in the USA rebuilds Skyhawk motors like
this one that makes 4.5 HP or the full race motor below
that makes 9.5 HP