Model # E200FHLSRC Serial# 5041689

Was running wide open yesterday when the engine hiccuped/surged then came off pad.
I tried to get back on pad, but engine will not go above ~1200 rpm.
Engine idles fine, but everytime I attempt to accelerate it gets to 1200 rpms then seems to start chugging like it floods itself out.
I would appreciate any suggested diagnosis.