Craftsman professional PYT9000 El Manual Del Propietario página 8

Sight and hold this levelwith a vertical tree...
or a corner of a building...
15 °
Use this page as a guide to determine slopes where you may not operate safely.
Donot operateyourlawnmoweron such slopes.Do notmow on inclineswith a slope in excessof 15degrees(a rise of approximately 2ol/2 feet every 10feet). A riding
mowercouldoverturnand causeseriousinjury.Operateriding mowersup and downslopes,neveracrossthe face of slopes.