Riding lawnmowers operate under dusty, dirty conditions. The underside of the mower deck inevitably becomes coated with grass clippings and dirt. If left untouched, this debris can cause rusting and may impair the mower deck's cutting ability. A deck wash kit makes it easy to flush debris from the deck's underside. Kits are available for specific brands of mower. There also are universal deck wash kits that fit many different mower brands.
Things You'll Need
Park the mower on a level surface. Turn off the engine, disconnect the spark plug, set the parking brake and disengage the blade drive before working on the deck. Deck wash kits consist of a deck fitting secured by a retaining nut and washer, and a matching garden hose adapter. Some kits may include drill bits for mounting. If your deck is larger than 42 inches, install a kit in the deck on each side of the mower.
Drill a hole through the deck. Use a drill bit the size specified by the kit manufacturer. Locate the hole on a flat portion of the deck above the blades, or where recommended by the kit manufacturer. If your mower's deck already has a plugged hole for a deck wash fitting, remove the plug and use that hole.
Push the threaded end of the deck fitting through the hole in the deck. Reach under the deck and use the retaining nut and washer supplied with the kit to secure the fitting to the deck. Use the wrench to tighten the nut. Some kits require that you drill one hole for the deck fitting and a second hole close by for a bolt and nut that secures the deck fitting in place.
Attach the male end of your garden hose to the hose adapter. Attach the hose adapter to the deck fitting in the manner specified by the kit manufacturer. Attach the female end of the garden hose to an outdoor faucet.
Reconnect the spark plug and start the mower's engine, ensuring the transmission is in neutral. Turn on the water and engage the mower blade drive. Throttle up the engine so that the spinning blades create a liquid cyclone under the deck that will flush away the debris. Keep flushing until no more debris comes out. Deck washing is most effective if done right after you finish mowing, before the debris can dry and harden.