Warm the engine up then cut at full throttle. A load on the engine will do a better job of seating the piston rings. Bearings don't need any break-in time. Oil & filter at 5 to 10 hours is not a bad idea.

Keep on smiling. NG is a great fuel for this application (unless the gas supply is interrupted). For folks who may not have natural gas service on their street, but would like most of the advantages of NG, Propane is a viable alternative. People who already heat or cook with propane (from a bulk cylinder on premises) have a fuel supply already in place. Other folks would need to transport small tanks of propane but the big advantages are in the clean burn and that the fuel never deteriorates (unlike gasoline).

Not sure about a single cylinder engine, but when I put a new cam/heads/intake on my 350, the proper engine break in procedure was to start the car and bring the rpms to 2000-2500rpm for 20-25 minutes to break in the cam. Then let it cool down. Change the oil and light on the gas for a 500 hundred miles. With a small single cylinder engine, I would start it up and let it run at about 1/2-3/4 throttle for about 20 mins and then let it cool down and change the oil. I would go through a tank or two of gas at no more than 3/4 throttle with a light load. After that the bearings should be worn in and the rings seated so you should be able use it as normal. I've never rebuilt a small engine, so I can't guarantee this is the correct way to break in a little engine.

While at Walmart today I priced out some different oils. I could get Supertech 15w40 (still CI spec) for 1.92/qt. Rotella T 15w40 for 2.22/qt, Rotella T Synthetic (CI spec) for 4.97/qt, Supertech 10w30 conventional for 1.92/qt, Supertech 10w30 synthetic for 2.97/qt, Valvoline 10w30 2.27 (but Pep Boys or Advanced Auto usually have sales/rebates for much less), or at the warehouse club Shell FormulaShell Full Synthetic for 3.33/qt. Straight 30w was a few cents cheaper than the conventional multi-weights. A wide range of choices, but not significant differences in price, at least for the few engines I take care of. In my mind, the Rotella synthetic is one of the better oils around and for 15 bucks a year I can service both engines needing a multiweight. However, I'm tempted to get a case of the Supertech 15w40 for break-in of any new engines in the future since it is still CI spec, but I suspect the shelf life would expire before dear wife allows another piece of power equipment, LoL.