coomarlin:

Well, I'm 99% sure based on the following:

1) They're 31cc
2) Same Ryobi 2-bolt cylinder casting
3) Same looking crankcase except for integral fan housing backplates
4) Carb & muffler both on rear

I'm not aware of any current trimmer engines other than Ryobi that have both the carb and muffler on the rear. Yes, they're both 2-strokes.