Automatic lubrication

Automatic lubrication (also called autolube or auto-lube) refers to a lubrication system where 2 stroke oil is automatically mixed with fuel and manual pre-mixing of fuel and 2 stroke oil is not needed. Occasional filling up of the 2 stroke oil reservoir is needed.

2 Strok oil pump on a Yamaha DX100- just behind the carburettor (to the left of the carburettor from the viewer's perspective). It is the primary component of 2 stroke Automatic Lubrication System. Amount of 2 stroke oil injected by the pump depends on the throttle position. A cable from the throttle is connected to the oil pump indicating throttle's position. A tube ensures flow of 2 stroke oil from the reservoir to the oil pump.

This system is popular with the users of 2 stroke engine, specially motorcycles as it eliminates the inconvenience and messiness of pre-mixing fuel and 2 stroke oil. Vespa Sprint is an example where pre-mixing of 2 stroke oil is required. Automatic lubrication was introduced for motorcycles by Velocette in 1913.^[1]

An example of application of automatic lubrication system is Suzuki AX100 motorcycle. The motorcycle has a separate oil reservoir on its right side which supplies the cylinder with 2 stroke oil proportional to acceleration.

Advantages of autolube

1. Consistent lubrication and oil consumption is reduced greatly
2. More effective lubrication results because the oil enters the engine in larger size droplets
3. There is much less unwanted carbon deposited on the spark plugs, cylinder heads, pistons and exhaust system.
4. There is much less exhaust smoke
5. Refueling is simplified

Disdvantages of autolube

1. The system is more complicated compared to manual pre-mixing, although it is easier for the end user.
2. For any reason, if the 2 stroke oil pump fails to operate properly, chance of damaging the engine is very high.
3. 2 stroke oil tank in a scooters or motorcycles is usually hidden from direct view of the rider and needs filling up occasionally. Without any indicator to indicate oil level, it is possible for a novice rider to forget to fill up the 2 stroke oil tank. This can end up starving the engine of 2 stroke oil and cause damage.

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