2001 Mercury Mariner 50-60HP Factory Service Manual, Page 241Get this manual
CYLINDER HEAD
Timing Belt Installation
Timing Belt Installation Notes:
Protect the timing belt from water and oilUse care not to scratch the beltDo not use any metal device to help stretch the belt onto the driven gear
1Align marks on driver and driven gear with marks on cylinder block as shown2Install timing belt onto drive sprocketSlide timing belt onto driven sprocket