Golf Course Management

FEB 2019

Golf Course Management magazine is dedicated to advancing the golf course superintendent profession and helping GCSAA members achieve career success.

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Page 35 of 121

32 GOLF COURSE MANAGEMENT 02.19 Two old diesel tractors recently lost a lot of power, and both sent smoke signals to let technicians know there were problems. Each problem was simply fixed, but each illustrated the need to remember the basic air-and-fuel simplicity of diesel engines and avoid over - complicated troubleshooting. A 1978 Satoh Stallion S750 started blowing nasty black exhaust smoke and would not get above 1200 rpm. e tractor is an "orphan." Satoh of Japan started in 1914, was absorbed into Mitsubishi in 1980, and in October 2015 the company became Mitsubishi Mahindra Agricultural Machinery Co. Ltd. ere's one U.S. Satoh parts distributor and no dealer net - work. But the 1.8-liter, 38-hp, three-cylinder Isuzu diesel engine had only 242 hours and ran great a month earlier pulling a 6-foot brush hog in foot-high damp grass. en a 1993 Kubota L2650 lost power, stumbled and stalled while brush-hogging. is tractor had under 700 hours and had always been reliable. e three-cylinder en - gine displaces 1.4 liters and puts out 29 horse- power. e owners called tractor dealerships and repair shops, asking for suggestions. Both were told they might need new injection pumps or injectors, or cylinder head rebuilds. To be fair, the phone technicians couldn't see or hear ei - ther machine. It's often best to prepare a po- tential customer for the worst. But none of the phone contacts suggested what turned out to be simple solutions. e Satoh's problem was lack of intake air. After 40 years, the cloth inner liner of a flex tube collapsed, partially blocking the path from the air cleaner to the intake manifold. A new intake tube was cobbled together. e Kubota's problem was that the fuel fil - ter had not been replaced for 25 years. A new filter cured the problem. Diesel engines need only a lot of air and little fuel to produce power. e Satoh's 1.8-liter engine draws in 0.9 liter of air for every full revolution (one intake stroke, one exhaust stroke). At 1000 rpm, it needs 900 li - ters of air every minute. at's about 240 gal- lons every minute, or 4 gallons every second. e partial blockage limited the air supply. e black smoke was unburned fuel. A diesel's fuel supply is regulated by a gover - nor in the injection pump. Push the throttle to accelerate, and you stretch a spring connected to a valve called the fuel rail. e cylinders get an excess dose of fuel, which increases power and engine speed. Higher speed increases the force produced by a set of spinning weights in the fuel pump. is force pushes against the spring and moves the fuel rail to cut back fuel flow. Until the spring and weights strike a bal - ance, excess unburned fuel shows up as black particles in the exhaust. Diesel smoke (shop) Scott R. Nesbitt e Kubota's owner had noticed the trac- tor's exhaust was cleaner than normal. e fuel filter was replaced, the engine again puffed a little black smoke when accelerating, and power was back to normal. Both old trac - tors finished early-winter weed cleaning and seemed ready for spring. Visit for two handy trou - ble-shooting guides for old diesels and newer emission-controlled engines to help sort out the possible causes of black smoke and other challenges signaled by the engine exhaust and other operating problems. Scott R. Nesbitt is a freelance writer and former GCSAA staff member. He lives in Cleveland, Ga. The inner liner of the air intake hose broke loose, partially blocking air to the engine and causing nasty clouds of black smoke and an inability to get above 1200 rpm. Photos by Scott R. Nesbitt Two large-bore radiator hoses, with a steel pipe inside to reinforce the joint, formed a new intake air hose and put this 1978 Satoh tractor back in full operation.

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