Could be a 5.2..The 5.2 and 5.8 had the same stroke, only difference is the bore..there are no more 5.8 Sachs chainsaws...
Makita bought Sachs a few years ago...The last large Sachs before the buyout was the Dolmar 9000, about 6 cubes and completely different...Too heavy for airplanes...
The 5.2 and 5.8 ran about the same, with the 5.2 being a little smoother....The 5.2 was model 133, the 5.8 was model 143.....