Equipment Focus: Aug. 1998, Power Is The Priority

If you were to relate a mower to a human body, the wheels would clearly be the feet and the blades or cutting deck would be hands. It stands to reason then that a mower’s engine would be its heart.

THE DURABILITY DYNAMIC. It’s no secret that contractors’ biggest demand of equipment is that it start when they need to use it. With mowers, that puts the emphasis on the engine.

“Contractors should look at how an engine is designed and constructed,” recommended Cameron Litt, product manager, Kohler Engines, Kohler, Wis. “For example, a cast iron cylinder will last a lot longer than an aluminum cylinder.”

Contractors should also be aware, however, of any trends influencing current engine development, such as an increased preference for liquid-cooled models.

“Generally, intermediate walk-behind mowers are powered by air-cooled engines because of the smaller size of the machine and the higher cost of liquid-cooled engines,” noted Mike Koppen, product manager for commercial mowers, John Deere & Co., Raleigh, N.C. “But the durability associated with liquid-cooled engines as mowers run in dirty, hot air is making them more popular on larger mowers.”

Litt noted that engines of less than 18 horsepower are almost exclusively of the air-cooled style, with engines from 18 to 25 horsepower available with both air- and liquid-cooled options and engines beyond 25 horsepower relying almost exclusively on liquid cooling.

“The liquid-cooled engine will be quieter, which is important to the mower operator,” noted Deb Szymczak, marketing coordinator, Kawasaki Motors Corp., Grand Rapids, Mich. “There’s also less vibration with a liquid-cooled engine and they’re easier to maintain.”

The overhead valve design of engines, described as a “new, old idea,” by Dick Tegtmeier, president, Encore Mfg., Beatrice, Neb., has also become popular.

“These engines seem to offer longer life, and they also have a full pressure lubrication system to let contractors mow sidehills without worrying about lubricating the engine,” Tegtmeier explained.

SWAP SHOP. Many contractors will run a mower beyond the life of the original mower engine, so the ease with which that engine can be replaced is important.

“Contractors don’t have to use the same brand engine if a replacement is necessary, although that’s generally what they do,” observed Szymczak. “They can pretty much put any engine on the machine as long as it’s within the same horsepower range as the original engine.”

Litt pointed out that there can be a few restrictions on replacement options. “Replacing an air-cooled engine with a liquid-cooled engine can be a big task because the latter requires additional space to install a radiator,” he said.

MAINTENANCE REGIME. Many headaches associated with repairing engines can be easily avoided, or at least delayed, with a simple maintenance program.

“On any engine, the key is maintaining it properly,” Litt noted. “That means keep the air cleaner clean, change the oil and clean the air filters.”

“We recommend checking the oil and filter every 25 hours of use, but contractors might want to do so more often if they’re operating the mower in particularly dusty conditions,” noted George Thompson, vice president, corporate communications, Briggs & Stratton, Milwaukee, Wis.

Bill Shea, vice president of sales and marketing, Ferris Industries, Ferris, N.Y., also noted the importance of purchasing a mower or engine from the proper dealer.

“Some dealers sell a lot of commercial equipment but aren’t listed as a dealer for that type of engine, so they may have difficulty getting replacement parts or servicing the machine,” he said.