Maintaining Your Cutting Edge

 September 12, 2013

A little maintenance goes a long way when it comes to keeping your Exmark cutting system performing at its best. In the heat of the cutting season, while you’re focused on cutting grass, it’s easy to let blade and deck maintenance intervals slip. It’s a common challenge, but when it comes to cut quality and cutting efficiency, it pays to keep blades sharp and belts tight.

Blade maintenance

The sharpness and overall condition of your cutting blades are extremely important to the performance of your Exmark mower. Here’s why: instead of cutting cleanly, dull blades tear blades of grass instead of cutting them cleanly, increasing susceptibility to dieback and pests. And due to their inability to efficiently cut grass, dull blades also increase the load on the engine and powertrain of a mower. This decreases fuel economy and increases component wear, leading to increased service costs and ultimately, a reduced lifespan for the mower.

For landscape contractors, the lost efficiency and increased wear and tear can significantly impact profitability. As a result, it pays to inspect the blades and deck each day, and sharpen/balance blades every 10- to 50-hours, depending on cutting conditions. Be sure to replace any blades that show excessive wear, especially where flat and curved parts of the blade meet. If significant wear or slotting is observed (see Figure 1), replace the affected blades with appropriate Exmark Original Equipment (OE) before mowing again. Exmark OE blades are engineered for specific cutting conditions and their use preserves the performance and long-term durability of the Exmark cutting system.

Figure 1: Replace worn blades if you observe signs of wear or slotting.

Since cutting conditions vary, it’s tough to predict exactly when blades will need sharpening, so many contractors will keep an extra set of sharp, balanced blades in the truck, ready to be rotated-in at a moment’s notice. That way they can continue cutting uninterrupted and can wait until they get back to the shop to sharpen and balance the blades.

Belt and idler pulley maintenance

Belt tension is an issue that Exmark users really don’t need to worry about, since the belts are self-tensioning. Because of this, service is reduced to checking the condition of belts every 50-hours and replacing as necessary.

Because belts stretch most when they’re first installed, it pays to stay on-top of belt tension adjustment on mowers that lack an automatic tensioner. Running a mower with loose belts significantly decreases the lifespan of the belts, so check their tension three times in the first 24 hours of use following installation, adjusting as necessary. After this break-in period, check belts every 50 hour of use, adjusting when tension drops below the specification in the owner’s manual.

It’s easy to check belt tension with a ruler and a fish scale. Simply hook the fish scale around the belt and pull, using the ruler to measure the belt’s deflection. Some Exmark belts are specified to run at ½-inch of deflection under 10-pounds of pressure. At this tension, a 10-pound load on the belt will move it ½-inch.

Idler pulleys should be clean and free of debris. An easy way to extend the life of idler pulley seals is to spray them periodically with spray lubricant. Exposure of the seals to the sunlight’s UV rays can harden the seals, reducing their effectiveness. A quick squirt of spray lube periodically keeps the seals soft and supple and helps them do a better job of keeping dirt out.

Of course, keeping the cutting deck clean and free of debris is extremely important to the overall efficiency of an Exmark mower. Each day, as you check the condition of cutting blades, be sure to also check the mulch build up under the deck, cleaning as necessary.

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