Break it in on the easy side, don't overheat it or overrev it, keep combustion clean, use good oils, don't crash it, and most engines will outlast you.

I called Dave, the owner of DA Engines and he basically agrees with the above statement. Saying few people see as many engines as he does, he recommends breaking in on petroleum oil to seat the rings and then switching to Amsoil Saber Professional 100:1. (10 years experience speaking) Not wanting to get involved in the public debate with the uninformed (my term, not his), he said running too lean, overproping, overheating is by far the biggest engine killer. He said his techs can look at the engine and tell what YOU did wrong. He acknowledges good oils of other brands will not harm the engine, use whatever you want. Fearing lawsuits, he won't say what the bad oils are, but they are out there: you won't be able to fool him. He agreed that breaking in on the rich side of lean to avoid overheating at high rpm is a good rule of thumb. Too lean is too hot, too rich causes carbon build up. Bench running may not alow enough cooling air. Heat soaking as mentioned above is OK, but not mandatory. Finally, break in time can vary, 50 - 2-3 gallons, 150 - 6-10 gallons. The owner should feel the engine loosen up over time, it runs smoother, better power and response. Flipping the prop on a cold engine to feel compression really doesn't mean much, because the rings need heat and pressure to seat properly. He rattled of a list of technical reasons why just because one oil works good in one application does not mean that it will work good in other applications. ie outboards are not airplane engines. (Sorry Desert Pig)

As a disclaimer, I will state that I have been using Amsoil in everything I own for years, technically I am an Independent Amsoil Dealer, although I don't sell enough of it to even make payments on a DA engine, and my mechanical background is diesel, automotive, and years of racing 2 and 4 stroke motorcycles. Amsoil is now making 4, that's right FOUR, 2 cycle premix oils. Saber Professional 100:1 is the one primarily recommended for air cooled carbureted engines, be sure to get the right one. I find many people who critisize Amsoil were not using according to recommendations or in correct applications. I will confess that in my 2 cycle dirt bike, I used 100:1 at 80:1. My fear factor. Yes, there are other good oils out there.