On my older single-blade mower deck Snapper rear engine rider, you loosen the clamp bolts on the main frame tube, and lengthen/shorten the position of this tube in the clamps to change the tension of the mower deck drive belt. Tighten clamp bolts after adjustment.
The mower deck spindle bearing has a grease zerk, give it a shot of grease once per year.
Disconnect the spark plug wire before doing any service work on any lawnmower.
haywiremechanic, June 2009
