Reading through many of the threads on here, I constantly read about break in oils, synthetics, etc. Some manufactures recommend brand "X" over brand "Y" or"X" amount of gallons of fuel on petroleum based oils, then switch to synthetic for proper seating of the rings. blah blah blah

We've all read these threads!

My questions is how do you know when the rings are properly seated?? When is the magic time to switch??
(and please don't say because engine manufacturer "A" says 2 gallons of petroleum base oil, then synthetic or manufacturer "B" says 10 hours on petroleum, etc)

I'm more curious as to a physical, or visual test one can do to ensure that his engine is breaking in as it should.

thanks
Sam

Sure. Take the ring off the piston and examine the wear surface in a scanning electron microscope. You should see a uniform surface topography.

Alternatively, you could use a leakdown tester. Compare the amount of leakdown from the fresh bore to X hours later after running. When the leakdown tests quit improving, it's broken in.

Unfortunately, they don't make engines like Butterball turkeys....no little doohickey pops up to tell you the thing's ready.

Two tanks of gas and mines not done yet

Sorry Sam, we're just funning a little.

When is an engine "done", turkey tester or not? This may be non-scientific, but you can just sort of tell. Once you fly the engine you get to know it. It flies just fine when new, usually on factory settings, then one flight it starts to "burble" just a little in the midrange. "Lean me" it's saying. From that point forward you have to lean the low end sequentially after every few flights - not much, maybe just a 1/8 turn or so. When you get to the point when it holds the setting for multiple flights and no more black goo is emmitted from the exhaust, then the engine is "done". Then, if you want, you can switch to synthetic oil. However, remember that modern two stroke non-synthetic air-coooled engine oils are very good and using them indefinitely will not endanger your investment at all.