yes, quality can vary tremendously.
the more expensive motors tend to be slightly better.
i recall my skyhawk black motor had a rounded cylinder rather than the standard square fins/head...rather unique, i thought.
it took a lot of abuse, lasted me for a long time then passed on to a friend for a few months. sorta feel like getting it running again
another engine, the cheapest available, turned out to be a 66, and everything about it was bad, never managing to get me simply 5km down the road without a failure.
usually, the self run businesses tend to sell better products than the "ebay" sellers. you need a good reputation to keep in business.
my three or four "ebay" specials always had issues, whereas buying from a dealer type person...usually much better.
once you use different vendors, the parts matching becomes a complete nightmare. different skirt heights, different deck heights, cylinder heights, rod lengths, eek...and not one part is labelled or numbered
