Technology is allowing them to pull power. Remember manufacturers know we expect increases so they sand bag and trickle us power. I’d be more concerned about electronics going haywire and us shade tree guys not being able to work on it in the long run.. (could M tronic survive an EMP?) These pro saws are truly bulletproof. I’m a tear up an anvil in a sandbox kind of guy and I run my saws like I stole them and I’ve never had any issues besides flat out worn out parts. Just don’t lean them out or straight gas them and they will run until worn out. I even run stihl 50:1.Thanks for all the input. One of the things I worry about with saws like the 642 is longevity. They keep squeezing more power out of a given displacement, and dropping the weight, and reducing emissions, it seems like something has to give. I sort of equate a 661 to a V8, whereas the 642 is ecoboost. Lots of power and efficiency out of the ecoboost, but more complex and seems to be more problematic in the long run. Tough call..
I have 2 440’s I have kept past what I normally would, one had needed a piston and rings (just lost compression from use), starter pawls, needle bearing the clutch rides on, and the other I had to put a mag on from some freak failure. I’ve had to fix a rope here and there and some stuff I flat tore up from abuse like broken felling dog spikes, a handle I broke when one came off my flatbed at 70. Tons of bars , chains, and rim sprockets. Mind you all that’s after each of these have cut more wood than a single family could burn in a lifetime.
I do think M tronic is the best thing for a saw a guy is gonna work for a couple years and then swap it for a new one. When I made a living with a saw I traded twice a year and for a long time had never put a part into a stihl saw besides consumables like bar, chain, rim sprockets, air filters. Nor had I even touched a knob on a carburetor, I never learned how to tune a saw before I started moding them, because I didn’t need to. They are amazing machines.