I have a 98' 150Ficht, updates, and all that- no real history of major problems/issues, (except only 120 hrs on it)- lately- at WOT, (5300rpm), I'll occassionaly get a 100-200 RPM loss, (via Dash tac), and they last 1/2 to 1 second, and vary in frequency- in a 2 min WOt run- I'll get anywhere...