I'm usually guilty of overengineering, too. But the nature of DIY often means stepping into the unknown when tackling a project. Despite any egos anyone may have, nobody ever always nails it the first time through. Furthermore, since DIY often involves components of unknown/questionable origin or history, there's going to be an inevitable element of surprise. Example- You just bought a 30-year old flatty on Craigslist for $20. You just gave it the once over- compression, spark, fuel, air. Cleaned and gapped plug, fresh fuel, one pull- vroom! Satisfied with your new purchase, you bolt it to Betsy there, and go for a shakedown run. BOOM! Bottom end lets go. You couldn't possibly have known that the previous owner to the previous owner had torn it down and when reassembling, torqued the rod cap nuts to "feels right", and put 'er back together...
The above example was straight out of my imagination, but happens all the time. The lesson to be had here is that it's par for the course, and you'd basically better get used to the idea. Your only other option is blow a couple of grand on something factory built, shiny new, and comes complete with a warranty...
