MAPPINGSet of reference values stored in the electronic control unit (ECU) memory, used to control the engine operation, especially as far as ignition and injection control is concerned.
MASS AIR FLOW (MAF) SENSORSThe Mass Air Flow Sensors convert the amount of air drawn into the engine into a voltage signal. The ECM needs to know intake air volume to calculate engine load. This is necessary to determine how much fuel to inject, when to ignite the cylinder, and when to shift the transmission.
MECHANICAL INJECTION SYSTEMS The K-Jetronic system operates by injecting continually, without an external drive being necessary. Instead of being determined by the injection valve, fuel mass is regulated by the fuel distributor.
MECHANICAL SUPERCHARGING The motive force used to power the mechanical compressor is taken directly from the IC engine. Mechanical superchargers are available in a variety of designs. A belt from the crankshaft usually drives the supercharger at a fixed ratio so crankshaft and supercharger rotate at mutually invariable rates. One difference relative to the turbocharger is that the supercharger responds immediately to increases in rpm and load factor with no lag while waiting for the impeller to accelerate. The result is higher engine torque in dynamic operation. This advantage is relativized by the power needed to turn the compressor. This must be subtracted from the engine's effective net output and leads to somewhat higher fuel consumption. However, Motronic can lessen the significance of this by controlling operation of a compressor clutch to switch off the supercharger at low rpm and under light loads.
METHYLCYCLOPENTADIENYL MANGANESE TRICARBONYL (MML) MMT is an organic manganese compound. It is used as a fuel additive designed to enhance octane levels in gasoline.
METRIC CRUISERMetric Cruiser is a general category of bikes including Honda, Yamaha, Kawasaki, and Suzuki as opposed to American bikes such as Harley-Davidson and Indian. The American bikes tend to use the English system of measurement: pounds, feet, miles, inches, while the Metric Cruisers use the Metric system of measurement: Kilograms, meters, etc. The fact that some American bikes may use the Metric system to quantify their components may still render them as American rather than Metric, at least in the eyes of the Metric Cruiser enthusiasts. By the way, the new Harley-Davidson V-Rod model is also a Metric Cruiser.
MIXTURE ADAPTATION The air mass required for the combustion is dependent upon the intake air's temperature. Taking a constant throttle valve setting, this means that cylinder charge reduces along with increasing air temperature. The Mono-Jetronic central injection unit therefore is equipped with a temperature to the ECU which then corrects the injection duration, e.g., the injected fuel quantity, by means of an intake-air-dependent enrichment factor.
M-MOTRONIC M-Motronic combines all the electronic systems for engine control in a single control unit (ECU) which, in turn, governs the actuating systems used to control the spark-ignition engine. Engine-mounted monitoring devices (sensors) gather the required operating data and relay the information to input circuits.
MOTOR OCTANE NUMBER (MON) The Motor Octane Number, or MON, is derived from testing according to the Motor Method. The MON basically provides an indication of the tendency to knock at high speeds. MON figures are lower than those for RON.
MONO-JETRONIC FUEL-INJECTION SYSTEM Mono-Jetronic is an electronically controlled, low-pressure, single-point injection (SPI) system for 4-cylinder engines. While port injection systems such as KE and L-Jetronic employ a separate injector for each cylinder, Mono-Jetronic features a single centrally-located, solenoid-controlled injection valve for the entire engine.
MONO-MOTRONIC The Mono-Motronic engine-management system is a low-pressure single-point injection system with integrated electronic map-controlled ignition. Combinations of the two subsystems enables joint optimization of fuel-metering and ignition-control.
MOTOCROSS BIKE A light-weight motorcycle specifically designed for racing on a track. As compared to off-road bikes, the suspension is able to handle harder hits, the power delivery is more explosive, and the gear ratios are different for riding on motocross or other closed-course tracks.
MOTORCYCLEMotorcycles are 2-wheeled vehicles patterned after bicycles, but with engines and much heavier frames. Early motorcycles were actually bicycles fitted with small internal combustion engines. There was a gradual evolution as numerous motorcycle manufacturers entered the market and competed against each other. Motorcycles have complex controls that are operated by both hands and feet and require coordination and skill not required to drive an automobile. Motorcycles have been a part of transportation for a very long time. They were once much more prevalent than automobiles until such pioneers as Henry Ford found out how to mass produce cars at a price below that of motorcycles. Over the years, motorcycles have come to fit a variety of needs beyond basic transportation. Today's rider may use a motorcycle for commuting and/or everyday use.
Some ride as part of their lifestyle and go on lengthy cross-country tours. Motorcycles have evolved to include 3-wheel vehicles called trikes. Motorcycles are sometimes fitted with a sidecar. In the United States, only one company, Harley-Davidson, has been able to survive over 100 years. Harley Davidson has been producing models every year since its first model in 1903. In fact, to most non-motorcyclists, the words "motorcycle" and "Harley-Davidson" are used interchangeably. Although many motorcycle brands exist, the most prominent besides Harley-Davidson are Honda, Yamaha, Kawasaki, Suzuki, BMW, and recently, American made Victory.
MOTRONIC Motronic combines the gasoline-injection and ignition systems to form a common engine-management system. The basic fuel-injection systems together with an electronic ignition form the basis for both the ignition and fuel-injection systems in the Motronic.
MULTI-POINT FUEL INJECTION Multi-point fuel injection forms the ideal basis for complying with the mixture formation criteria. In this type of system each cylinder has its own injector discharging fuel into the area directly in front of the intake valve.