The red lever came on the first year or so on the 026 run, and was not significant. Red or black, they run the same. The clear or solid gas tanks appeared on PRO and non-PRO saws throughout the 026/260 production runs, no rhyme or reason. The early model 026 saws had the most open mufflers, and they were choked up over the years with 2 much more restrictive types. Same with the carbs, the early and mid year models had fully tuneable carbs (Walbro 194 and 22c) and the late model 026 and early 260 saws had fixed H jet carbs. The early model 026 saws have aluminum top handles, the mid year and late 026 and 260 models have composite top handles. The early 026 starter housings were metal, later model years were plastic. The early and mid year models have a smaller AF and no compensating carb with a tower tank vent. Late model 026 and 260 saws have larger air filters and compensating carbs, as well as 2 different low profile tank vents. The late model 026 and 260 saws also have a different AF cover with a lever instead of a knob. The 026 had a 44mm P&C, as do some very early 260 saws. The later 260 saws have a 44.7mm P&C. The 44 and 44.7mm P&C can be swapped between 026 and 260 saws as a set. Some 026 saws have a plastic oil bump body, and some have a metal one. The 260 has the flippy oil and gas caps, the 026 saws had screw in oil and gas caps.
The only difference between the PRO and non PRO 026 and 260 saws are that the PRO saws have an adjustable oiler and a decompression valve. And the PRO sticker. There were no other differences. I had one 026 non PRO saw with the PRO chassis with the slot for the adjustable oiler and the oilomatic 'dial' cast in the frame, but it did not have the adjustable oiler. 5 o'clock special? My earliest one was made in 'West Germany', the others were made in 'Germany' (after the wall fell) or in the US. The non-adjustable oiler oils fine, it just puddles a tad at idle as it runs off the crank and not the clutch. No real need for a decomp on this small of a saw. I have had lots of these saws (all bought used) and several had some swapped later and earlier model parts on them. Its pretty much mix and match. I swapped a lot of parts myself between my 026/260 saws. I put a new OEM 260 44.7m P&C on my 026 and it runs great. I put the early model mufflers on them that are more open or drilled the mid year mufflers out more, and swapped in Walbro 194 adjustable carbs if they did not have them.
