Re: Brand new engine LOCKED UP
With the head off the motor should turn over super easy... Unless there is something you're not seeing causing friction between your cylinder and piston I would say you had a bearing in the bottom end die on you. As to why? Probably just a crappy part or something was poorly assembled.
The manuals suggest break-in mix should be 16:1, most people say that's way too much oil. I usually run a first gallon of 20:1, second gallon 24:1 (which should take you a couple hundred miles), and then move to 32:1 from then on. That said, I'm pretty sure your 25:1 mix should provide enough lubrication, but during the first 100 miles I tend to run just a little bit more oil because the parts in these motors can start out pretty dry and that extra oil in the first gallon helps get the oil where it needs to be faster.