Sharpen mower blades to an angle of 30 degrees for best cut and durability. Sharp blades require less power for operation, thus less fuel consumption and wear and tear on the engine and drive components. Dull blades will bruise and tear grass leaf blades and can create openings into the plants for disease to invade. Inspect the v-belts on equipment for wear and cracks. Frayed edges on belts and cracks on the bottom side indicate wear and age.
Worn belts tend to stretch and slip on pulley drives which reduces power and efficiency.
Replace worn or damaged belts with proper size and type belts. V-belts for automobile applications are not a good option on lawn and garden equipment. Lawn and garden equipment belts are stronger and will usually last much longer. Belts that are slipping may only need adjustment of the pulley spacing or you may need to apply a belt dressing to the sides of the belt to return them to operating condition. Remember that new belts will stretch slightly after installation and use and will require re-adjustment after a few hours of use.