Re: Running again, break in/heat question
One: I have to think it's sticky from sitting, and it'll loosen up. Three: I would put the pipe on for break-in. Not only does the pipe push the fuel/air back into the cylinder before the exhaust port closes, but it also pulls the exhaust - and by extension, the new charge of fuel/air - when the exhaust port opens. Better flow, more fuel, more oil, better lubrication.
Now, two, heat. If it's running lean, it'll run hotter (I think). Check your plug. You might want to break in with regular oil, too.