Hi Whitewill1412. That's a very good question because it led to some insightful responses. I remember back in 2008 or 2010 someone asked a similar question as yours except about the Grubee 2 stroke bicycle engines. Back then Grubee had the same highly respectable reputation as the Zeda 80, and coincidentally, back then I believe the good people at Bicycle-Engines were one of or the only dealer for Bird Dog Distributing's Grubee engines. @2008 or 2010, the responses about the Grubee engines were similar to the Zeda80 in that some experienced builders stated that less expensive generic engines were just as good as Grubee's, and other knowledgeable builders said there was no comparison, Grubee engines were superior. I don't know how to answer your original question except that Zeda80 engine's higher quality is probably more consistent than engines from Motos, China Raw or the other brands I can't think of now because of wine, being tired and old age.