Most Lawnmower Trouble Caused By Neglect

Press, Volume CX, Issue 32209, 30 January 1970, Page 6

Most Lawnmower Trouble Caused By Neglect

Many lawnmowers work inefficiently, are difficult te start, labour instead of run smoothly and cut raggedly. Usually the trouble ean be rapidly pinpointed —owner neglect The most common faults are the following: (1) Worn or dirty spark plugs. (2) Dirty | air cleaner. (3) Dirty fuel I system. (4) Blocked and/or (dirty cooling fins. (5) Dirty {engine oil. (6) Damaged or (blunt blades. (7) General (lack of lubrication. (8) Loose lor missing nuts and bolts.

Spark plugs on small engines do not last as long as they do in a big one. To operate efficiently they must be clean, properly set and the electrodes in a good state. Emery paper can be used to clean them and a feeler gauge used to set the gap between the centre electrode and the earth (normally about .025 in Reference should be made to the operating manual supplied with every machine These checks should be made every 50-100 hours of operation, depending on the conditions under which the machine is used. A fouled plug—carbon, soot-covered or very oily—is probably indicative of fuel problems. This occurs more often than not with twostroke engines which use a 1 mixture of oil and petrol. {Unless ready-mixed two(stroke fuel is purchased, mixling should be in correct proportions—half pint oil to gallon of petrol—and prepared , before pouring into the mower’s fuel tank. The two fluids should not be poured into the tank separately. Check also for cracked or loose plug wire and connection. Dirty air-cleaners account for a considerable proportion of malfunctioning engines. {Under dry and dusty conditions air cleaners will clog up (rapidly and periodic inspection and cleaning should not

be overlooked. Discard old oil from oil-bath cleaners. Wash the element in petrol and refill the bowl to the level indicated—not above. Excess oil may be sucked into the engine and cause starting problems. Metal foil, dry or spounge filters more commonly used today, should be dunked in petrol and in the case of spounge pads lightly soaked in oil before replacing. Fuel systems can become dirty and clogged quite easily. Sediment can enter the tank when the filler cap has been removed, or via unclean fuel which is often the result of a dirty can. Clogging of the system can be caused by the evaporation of fuel in the carburettor, as fuel is usually left in the carburettor when the engine is switched off. If the mower is not going to be used for a day or two turn off the fuel supply at the tank and let the engine stop by consuming the fuel left in the carburettor. This minimises the formation of varnish within.

The system can be kept clean by using a filter funnel to pour fuel into the tank. Periodically the tank, carburettor fuel line and filters can be dismantled and thoroughly cleaned and also checked for wear in the process. Another easily overlooked matter and one which can cause starting and running problems is the fuel tank cap vent hole which must remain open. Dirty cooling fins are a major cause of over beating. These fins are usually covered by a metal shroud. In consequence it is not always apparent that they have become dirty and the amount of rubbish of various sorts they can accumulate in a short time under arduous working conditions would surprise many people who have never examined their machine pronerly. The air intake housing .must be removed before it is possible to push out the accumulated rubbish from between the fins. Overheating can also result from ar. accumulation of carbon in the muffler and exhaust port The muffler can usually be removed quite easily and the carbon deposits tapped and scraped out Similarly the exhaust port can be cleaned out By cranking the engine any loose carbon can then be blown out Dirty engine oil can cause

rapid wear on four stroke petrol engines. It should be completely drained out, the sump flushed thoroughly and then allowed to drain and dry. Refill with the recommended grade of oil, after the specified period of time since the last complete change, normally about every 25 hours of working time. In between this period regular checks should be made before and after use to maintain the correct level, but not above it. Often the engine may show signs of labouring in rough going or thick grass. This could be due to nicked or blunt blades. Blades which are out of balance, and this is particularly applicable to rotary types, can cause enough vibration to severely damage the engine. Rotary blades can be removed and set up with the centre hole across a thin edge. If it cannot be reground and balanced in this position buy another one. A cylinder reel should cut evenly over the whole length of the sole plate It can be tested with a sheet of paper held between the reel and plate and the reel slowly revolved. Manipulation of screws at either end of the reel will bring about the necessary setting. Sharpening of such machines is usually an expert's job. Lubrication of wheels,'controls and the inside of wire sheathing can greatly prolong the life of the mower, prevent breakages and Senerally facilitate better andling. A timely dab of oil here and there where It is needed can work wonders and yet the oil can and/or grease gun are items which appear to be unknown in many gardens. No machine will run for ever without some nut or bolt working loose, perhaps shearing and becoming lost A regular check pays dividends in keening the machine in top working order and ends those frustrating breakdowns in the middle of the job. Keep a record of the servicing carried out and log the number of hours the mower works. And in conclusion a suggestion: thoroughly clean the whole machine each time after use —it will not only make for better mowing but prolong the life of the machine and will result in a far better trado-in price later on.