I was riding my newly assembled Grubee 4 stroke when the engine made a loud ping sound and died. I pulled the spark plug off and looked at the head while rotating the shaft and it did not move; Most likely broke the connecting rod. So now I'm wondering if I fix it that it's going to break again after another 50 miles, or should I cut my losses and consider getting a more durable engine. If I get the Honda 50, will I be facing the same problem?

Seriously though: Whats the harm in ripping it apart for a post mortum? Least we'll know what happend and if you can fix it for a few bucks what the heck? As to adding oil... I once had a very experienced mech rebuild my supercharged Mazda Miata motor after blowing it up on his dyno.. When they went to start it nobody checked the oil pressure. Oil cooler araingment on this particular car has a one way check valve. Yup. Hoses to the cooler were reversed and NO oil pressure. Ran great till the exhaust cam siezed and snapped in two.
Even the best of us can have a very bad day.