ninayu61 said:
Anyone know why the US versions did not get the lambda sensor and the EU bikes did?
I don't really know but would take a guess it might have something about meeting government emission regulations. IMHO (could be wrong) an EFI system setup with a O2 sensor in theory would have a better chance of meeting regulations
ninayu61 said:
Anyone know the reason for lambda or not to lambda sensor?
The Lambda Sensor or as it is also known O2 Sensor or Oxygen Sensor is there to measure the unburnt fuel in the exhaust system. The O2 sensor outputs a very small voltage according to the ratio of air and fuel (maybe oxygen and fuel I am not a scientist so not 100% sure on that bit) in the exhaust system. That voltage is fed into the Keihin EFI computer under the seat.
EFI Computers work in 2 modes. Open Loop and Closed Loop.
Open Loop is without the input of an O2 Sensor. This works fine and is used in many EFI systems. Some of the most powerful EFI Twin Turbo Big Block Chevs boats that I have seen run Open Loop EFI mode without the use of an O2 sensor. I run Open Loop in my Fuel Injected Boat. Open Loop is just more simple/basic and works perfect.
Closed Loop is when the EFI system looks at the input of the O2 sensor and makes fine adjustments to richen or lean out the engine. It is normally only done on light/coasting type engine loads or deceleration (going Down Hill). When held at Wide Open Throttle (WOT) the Closed Loop EFI systems as I understand it goes back to Open Loop mode and ignore the O2 sensors input.
"Closed Loop" means the engine looks at all the sensors (but not the O2 sensor) and the result is to fire the Fuel Injector and then takes a reading via the O2 Sensor in the exhaust to look at the result of what it did, and feeds the info back in the ECU and make an adjustment if required for next time it fires the Fuel Injector. The ECU fires the Injector, looks at the O2 Sensor and potentially changes what it does next time based on what is sees from the O2 sensor. It "loops" the information back into the ECU.
The ECU can keep the Injector open for a shorter period to make a leaner mixture or hold the Injector open for a longer period to make the mixture richer.