Ok, I have heard a lot about the 262 having different cylinders. I know one is preferred, but don't know why, or what identification markings it would have on it. Also, approximately when did the cylinders get changed.
As far as I know, most of the really early ones were KS (KolbenSmidt) non-decomp ones, and the KS ones are held in the highest regard because they had a smaller combustion chamber than the Mahle and Gilardoni ones (with or without decomp).
I don't think we ever will know the full story of the different OEM cylinders and the carbs and gasket thickness they were combined with on stock saws though, but we know what the most common combinations were, and
about when they happened. Surprises keep turning up though....
As far as I know, all the Swedish made 262xp saws were rated at the same 3,5 kW/4.8hp, but some late ones (after 2002) that were sold in Israel, Russia and maybe other east European markets up to about 2006 had a rating of 3.4 kW/4.7 hp. I suspect those late saws were made in Brazil, but I don't know it as a fact. Another possibility is that they were made at the Tomos/Koper factory in Slovenia. The last version to go off the market was the very different 262xph in Russia, but I don't remember exactly when.
The 262xp is one of only two saw models that I
know came with OEM cylinders from all the 3 best reputed cylinder brands, the other one is the Jonsered 670 Super/Champ.
Attached is a Gilardoni cylinder on a 1991 262xp. There were non-decomp Mahle ones as well, not just the decomp ones introduced some time in 1994.
The DLG test report from 1997 showed 3,6 kW/4.9 hp - but I don't know if they actually dyno tested a 1997 saw, or if they "recycled" the dyno results from 1992 (those test reports were renewed every 5. year).
http://www.dlg-test.de/tests/4600.pdf