I have many Saitos. Very dependable. Strong. Great sound. The four-stroke engines have been around for years and can take an incredible beating. I have driven them straight in the ground from an unplanned vertical dive (ok, crash!), pulled the engine out of the ground, cleared the dirt from the carb, installed the engine on another plane and flew again the next day. Heating is no problem as long as you do not run them lean.

The OS engines are fine. I also own a YS-120, etc. but I keep going back to my Saitos. I buy them used on eBay or from other rc'ers with nary a problem ever. Parts are always available (many interchangeable). If one is totally misused and needs a bearing replaced, not a problem ... standard or ceramic bearings are easy to replace.

I rarely (I mean like once a year) make a minor adjust on the hi needle. Once broke in, I adjust the low end needle once period. That's it. I run all my engines on Wildcat 2/4 cycle 20/20 fuel (also called YS-20 fuel).

Enough?