Because the MS250 (mine at least) is a POS. Hard to start, hard to re-start, nothing to brag about when running.I’m not sure why anyone would bother with a 35cc to 40cc saw when you can bump up to a 45cc Stihl ms250. The ms250/025 has a great power to weigh ratio and loads of interchangeable parts giving you ample options between 3/8lp and .325 pitch. Spur or rim sprocket. It’s been my experience that echo makes a nice saw but echo has the habit of not supporting there older saws when it comes to parts availability. Of course this is my own opinion!
My ~35cc Echos (346 and 352) start and run well - and are lighter.