InMaintaining Small-Farm Equipment: How to Keep Tractors and Implements Running Well, Steve and Ann Larkin Hansen equip readers with their experienced guidance to sustaining smooth-running farm equipment that will last for years and save on costly services. With their clear-cut instructions and service tips, readers will learn to pinpoint problems before they get out of hand, as well as the tools and knowledge needed for basic repairs. The following excerpt is from Chapter 7, “Repairs.”
Fuel System Repairs
If the engine seems not to be getting fuel, turn the fuel line shutoff valve to “off,” then remove the clamps that connect the line to the gas tank and carburetor. Open the valve, and see if fuel drains at a decent rate into a container. If not, clean out the line, and any screen in front of the carburetor intake, or replace the fuel filter. Reattach the line, and turn on the fuel valve. If the engine is still not getting gas, the problem may be in the carburetor.
When cleaning or adjusting a carburetor for idle speed and richness of the gas/air mix, it’s best to use a detailed instruction guide or seek the help of an experienced person. Any carburetor disassembly will require a new gasket kit to avoid leakage. Note that working on a carburetor will often void the warranty on a new engine.
Electrical System Repairs
If a battery is not delivering a charge to the electrical system, clean any debris off the top of the battery, since this can cause a short between the terminals. Then clean any corrosion off the terminals and cable clamps with baking soda and water, or by sandpapering the contact surfaces. When they’re clean and bright, apply a light coating of dielectric grease or light lubricating oil, reinstall the battery cables, and see if the engine will start.
If it doesn’t, charge or jump the battery, and try the engine again. If the battery won’t hold a charge, then replace it. This is a simple and common repair: Loosen the nuts on the bolts that hold the battery cable clamps tight on the terminals, then gently wiggle the clamps off the battery terminals. Take the battery to a farm store or battery store, buy a new one of the same size and power rating, turn in the old one, and install the new one. Be careful of any leaking battery acid — this is hydrochloric acid and will burn holes in clothes and skin.
If the battery is good but the charge is being drained, there’s a short elsewhere in the system. Wiring and connections can cause a short because of looseness, corrosion, breaks, or frayed or gnawed insulation letting a naked wire contact metal. New wire and connectors are cheap and not difficult to replace, but it can be a long job finding the short circuit.
Other Electrical Components
Replacing a bad spark plug is simple; pull off the spark plug wire, then use a spark plug socket on your socket wrench driver to unscrew the plug and install the new one. Bad spark plug wires and distributor caps are simply removed and replaced by hand. On engines with multiple plugs, be extremely careful to put on the spark plug wires in the exact order they came off cut-off both the plugs and the distributor cap. Put masking tape tags on each wire and number them before removal, or just remove one wire at a time. The rotor under the cap easily slips on and off a rotating shaft, also making this simple to replace when faulty. The points are an interrupting switch that sit near the rotor at the base of the rotor shaft, and should be replaced if you’re replacing the rotor. The gap space on the points should be set according to the manual’s specifications at the most open position.
Replacing failed ignition switches, distributors, coils, generators, and alternators is well within the reach of the farm mechanic, as is adjusting the timing (you’ll need a timing light), if you find a good set of directions for that piece of equipment, and perhaps some advice or hands-on help from a more experienced mechanic.
The most common problems with a coolant system are a failed radiator cap, which is easily replaced; a blown hose; and a failed thermostat. Hoses and thermostats are simple to replace; the hard part is disassembling things to get at them. Be sure to purchase and install a new gasket if you put in a new thermostat.
We discussed replacing hydraulic hoses and connections in chapter 5. Hydraulic cylinders fail only rarely, and smaller ones are not expensive to replace. If there’s a repair shop in your area that deals with cylinders, you may be able to have yours repaired rather than replaced, but first make sure that is the cheaper option. To put on a repaired or new cylinder, unscrew the hoses to remove the old cylinder, attach the new one, then add more fluid to the system to fill the new cylinder. Start the engine, and pump the levers a few times to work air bubbles out of the system, then recheck the fluid level and top off as needed.
Replacing a Bad Muffler
On old tractors, mufflers are usually held on with a clamp or a similar system, so that replacing one is a simple matter of removing the old, buying a new one, and putting it on. It’s not necessary to have a specific make of muffler; it just needs to fit on the exhaust pipe.