RE: 90 sized engine recommendation
I have an OS 120AX, to much I think. I have 4-5 Magnum FS's (can't remember) really good and at the present prices hard to beat.
Jayhawk stated that he preferred a 2 stroke so I by passed the 4 strokes. My ST 90 took time to run in but after a gallon or so it is
really hard to beat all around.