Hello klausm, I too have had the dreaded engine seizure on TWO FG33R3 engines! Just so you know, I have purchased two of these engines and both have seized up and been returned. Unfortunately, I should have not got the second one until I had used the first for a couple of months. Visually and size wise its a perfect engine for the size of planes I use. One of the engines went back to Saito in Japan and has been repaired. The second was replaced by a new one which they broke-in with a gallon of mineral oil 20:1 gas fuel. I continued with the break-in for a further gallon of synthetic (Klotz Super Techniplate). Then
after the last tank on the plane, I stopped it after idle cool-down only to discover a half an hour later that the engine had seized! Still have not flown the engine in any plane as I do not have the confidence in it.