Especialidades JA/Motores pequeños/Respuestas

Motores pequeños

Nivel de destreza

2

Año

1975

Version

25.11.2024

Autoridad de aprobación

Asociación General

1

Describir el diseño y el funcionamiento de los motores de dos tiempos y el motor de cuatro tiempos.

2

Nombrar las partes de los motores de dos tiempos y decir lo que hace cada parte.

3

Hacer una lista de cuatro combustibles utilizados en motores pequeños y explicar su uso.

4

Demostrar el cuidado y la seguridad en el manejo del combustible y su almacenamiento.

5

Describir tres clases de sistemas de encendido.

Material for this section was adapted from the Wikipedia article on Ignition Systems

Glow plug ignition

Glow plug ignition is used on some kinds of simple engines, such as those commonly used for model aircraft. A glow plug is a coil of wire (made from nichrome normally) that will glow red hot when an electric current is passed through it. This ignites the fuel on contact, once the temperature of the fuel is already raised due to compression. The coil is electrically activated for engine starting, but once running, the coil will retain sufficient residual heat on each stroke due to the heat generated on the previous stroke. Glow plugs are also used to aid starting of diesel engines.

6

Explicar por qué la gasolina es un líquido de limpieza inadecuado.

Gasoline is extremely flammable and dangerous to work with. It is also a carcinogen (cancer-causing agent), so prolonged contact with it should be avoided. It can also damage plastic parts. Gasoline left on parts can burst into flame at the slightest provocation, causing an engine fire. It also has many additives, some of which stay on the part after you clean it. They also soak into your bloodstream.

7

Hacer una lista de dos líquidos de limpieza aceptables para los motores pequeños.

Mineral Spirits are often used for cleaning parts. Soaking parts in mineral spriits removes oil and grease without the need for scrubbing. Once the parts are removed from the bath, the mineral spirits quickly evaporate.

8

Hacer una lista de tres sistemas de lubricación y decir cómo funcionan.

• Splash: In a splash lubrication system, dippers on the crankshaft are repeatedly submerged and lifted out of the oil in the oil pan. This happens as the crankshaft turns. When the dippers emerge from the oil bath, oil is splashed all about the inside of the chamber where it finds its way to the pistons, rods, and other moving parts. Channels are milled in the crankshaft to direct oil flow from the dippers to the bearings in the crankshaft, as it is vital that these receive plenty of lubrication.

9

Hacer una lista en orden de los pasos generales del procedimiento de buscar la solución de problemas a los motores.

Remember the acronym FAST - Fuel, Air, Spark, and Timing.

10

Demostrar que usted puede revisar, inspeccionar y ajustar adecuadamente cualquier motor pequeño.

Consult with a Qualified Person for this part! Don't just tear into the family lawnmower, and hope you can get it all back together. You are likely to end up with "extra" parts left over when you are done! (which is not a good thing)

11

Demostrar que usted sabe cómo poner a prueba y limpiar las bujías y los tapones de calentamiento/bujía incandescente.

A toothbrush can be a good tool to clean spark plugs. (Don't use it to brush your teeth afterwards though!) You also need to use a spark plug gap gage, or a feeler gage to set the spark plug gap according to the engine specs. When cleaning them, you just need to get all the carbon and soot buildup off. These days, sparkplugs are usually just replaced if they are full of crud.

Referencias