MY exploration and research suggest that each engine use has a different bearing need... and the economy Boca or similar version is not necessarily the best economy or long life idea

That said, almost every thing I read suggests that for a 2 stroke IC, fuel oil bath engine, a sealed and pre greased bearing is not a good idea...while for a 4 stroke there is a good argument for them

I also think I learned, that in some applications, ceramic was good but in some (combat dirt) harsh environments the steel with full complement balls was better

Many many different schools of thought about shields...but common to my research was a front ball bearing should have the interior shield removed but leave the front facing shield in place allowing fuel and oil into the bearing but not out the nose of the engine...made sense to me...

arguments against this configuration suggest you need the flow of fuel oil THROUGH the bearing to flush contaminates out of the ball and race...again making some sense

same with rear bearing..on 2 strokes they recommend both sides open to get flow of lube in and contaminates out

I looked and searched for typical (ones I have) engines and empirical reports on bearings, life expectancy, rusting, failures, RPM ranges and found no such testing or experiential analysis...just a boat load of anecdotal reports

If I was serious competition guy I would look hard at high zoot ceramic.... but for sport long term use it seem to me the standard replacement bearing is very good from each of the few suppliers or factory item (if  can be found)

I did order my Nelson N.36c with ceramic rear bearings....but can NOT attest to if they ARE, or are not, BETTER

     I'm flying Navy Carrier and the motors that I use are maxed out on every flight. I've tried glass and standard bearings and don't see any difference. The bearings that have failed have  "no" lubricant in them when I take the motor apart and the shields or seals are ground up along with the rest of the motor innards. Instructions say put HS oil on the surface of the shield or seal between each flight and so far when they fail there is no lubricant there? So a shield bearing I would think would be ideal but have never found a bearing for these motors that says it is a seal bearing and require no lubricant at any time. My feelings are that these motors made in China are built cheap because that is what the American people demand. I have a couple of AXI motors that I purchased around 10 years ago and they are still running on the original bearings but these motors are not very high KV motors. The bearing in these motors are larger than the Chines stuff and just plane look like a good bearing and probably are as opposed the Chines stuff. How long until the land fills are full?

Motorman... all I can say is DOH! as I slap my forehead...

Daily, I just click the "show all unread posts since last visit" and most of the time assume all are from the "open forum"
I will try to pay closer attention starting today

If you once put liquid oil to bearing, you must repeat it till end. It will dissolve original lubrication out. So it can be good practice on cheap motors with cheap bearings, but good motors with quality bearing will work many hours without lubrication (with original grease).

Another problem with oiling is, that motors have usually 3 bearings, and oiling on that middle one which is hidden inside, is not easy.

However the best you can do for bearing is 3 blade prop :- ))