First 4 stroke?<div>OS, period.</div><div>And don't mess around, get a 1.20 (with a pump if you feel for it) and smile.</div><div>My 4 stroke collection consists of 9 YS's, and an old Enya .41 and an even older OS surpass 1.20.</div><div>For general use, the latter two are light years ahead the the former 9.</div><div>Get the picture.</div>