with a 58mm bore you have an 076AV
075 has 59mm bore
both have 42mm stroke.
Both saws have indentical engines: Same bore and stroke, 58mm x 42mm.
The differences are subtle, and as continue to work on my 076, I uncover more details.
--076 has oil cap on the side of the case, 075 is on top
--076 has hand guard mount on the crankcase, the 075 has it as part of the wrap handle assembly
--076 has a taller intake block resulting in a taller looking air filter. (I'm not sure that this change is present on all 076s.)
--076 coil is different: the high tension lead leaves the coil upwards and then heads back to the spark plug. The 075 lead just goes straight back.
--075 will not have the pawl-style recoil that the 076 and modern saws have. It uses the older Fairbanks-Morse friction shoe.
--076 will probably not ever have points ignition.
--According to the repair manual oil pumps have changed, but I think it occurred during the 075 production run.
--No IPL I've seen shows the 075 with a chain brake
Now, most of these points are debatable, even irrelevant, as it is easy to mix and match parts from 050, 051, 075, 076, and the related chopsaws. So, to me, the main distinguishing characteristics are the first 3.
Chris B.
