I found this site on a web search. I found this topic interesting so I researched it further. The only manual I could find on the 090 was in German it took me a bit but I tranlated it. So here it is the difference between an 090 and a ms 880. A ms 880 has a displacement of 121.6cc (7.42 cubic inches) and a hp rating of 8.6. The 090 has a displacement of 137cc (8.36 cubic inches) and a hp rating of 8.5. The conclusion is this, the 880 has .1 more horsepower and the 090 has .94 more cubic inches which in most cases means torque. In my opinion that makes them both equally superior!