Chapter 6 Basic Small Engine Maintenance and Repair Projects
Engine oil used in small engines should be changed every 25 hours of operation or once per season.
Used oil and soiled rags should be disposed of in accordance to local environmental statutes.
Several different steps are required to properly remove debris from a small engine.
Accumulated grease can be removed from OPE by using a degreasing agent and a pressurized water hose.
A spark plug gauge is used to adjust and measure the gap between two electrodes at the tip of a spark plug.
A spark tester is used to test the ignition system of a small engine.
A visible spark is present in the window of the tester when the ignition system is functioning properly.
A spark plug is tested for spark miss after the ignition system proves to function properly.
An attachment screw must be loosened to remove the air cleaner assembly cover on most small engines.
Foam air-cleaner elements must be saturated with engine oil prior to installation.
Dual-element air cleaners contain foam precleaner and a pleated paper element.
Many precleaners have installation instructions printed directly on the surface.
Air-cleaner cartridge housings should be cleaned with a clean, dry cloth instead of solvents or compressed air.
A muffler that is attached to an engine with bolts can be removed by loosening the bolts with a socket wrench.
A muffler that is screwed directly into an exhaust port should have penetrating oil applied to the screw threads prior to removal.
A threaded muffler can be removed by grasping with slip-joint pliers and rotating counterclockwise.
Hard soot accumulation in a muffler can be removed by tapping the muffler body with a rubber mallet or on a hard surface.
Some lawn and garden tractors are equipped with mower decks that can be easily removed or installed using a quick-disconnect mechanism.
Shear pins are designed to reduce component damage by fracturing when the driven member of a rigid system requires more power than a disc or coupling is able to provide.
Two-stage snow throwers typically have skid shoes to help provide smooth movement of the snow thrower along uneven surfaces.
Testing engine compression verifies the maximum power output of each piston stroke.
Testing a crankcase breather ensures that crankcase gases are properly vented.
When preparing a lawn mower engine for long-term storage, the moving components should be lubricated lightly with spray lubricant. Each lubricated component should then be actuated to spread the lubricant evenly into the moving parts.
Prior to long-term storage, the belt drive systems of mower deck blades should be examined for worn, scorched, or misaligned belts.
There is often an idler pulley connected with linkage to the clutch pedal of ride-on lawn mowers.