All up to you mate.

The Oz $ value for your country that has worked for the past few year has been $20.00 with no duty, I just looked at my records & I have posted to your country 12 times this year with no reported duties been paid, for other countries I put $25.00.

Yesteday i got hold of a FI diagnostic tool (secondhand at a good price :-) )

My throttle is between 17% closed and 98% fully open. Which is ok values according to the service manual.

How does the ECU determine the 20% to switch between closed and open loop ?

In short:
via voltage, the ECU can't read % it reads voltages, it displays % as a reference.

In long:
There are quite a few tables in the ECU but the 4 main mapping tables are:
F fuel tables via TPS/RPM inputs = open loop
L fuel tables via intake air pressure/RPM inputs= open loop
O2 sensor voltage inputs = closed loop. Closed loop is turned off/on via F/Ltrims/RPM/coolant temp
Ignition tables

The F/L switch point tables are preprogramed by Yamaha, the reason they use pressure as well as the TPS is so the ECU can determine engine load after the throttle plate & alter the pulse modulated width signal of the injector as the pressure changes even though we may not have changed the throttle position the ECU constantly adjusts the A/F ratio. The ECU can switch at any time between the F/L trims according to air intake pressure or throttle position.

The reason I am mentioning the above is there are many variables that can change the way the ECU used the mapping which affect the switch points in the ECU from open to closed loops.

I could go on for hours about mapping so I will end off here.

:-)

I had just hoped that there was a simple way to tell when when the motorcycle is running in closed loop based on rpm and gas handle - but makes sense that the other sensors are also used.

Actually I also wonder why the O2 sensor is only used at low rpm / throttle.

Thought that it would also be an advantage to use it as an input at higher loads instead of fixed tables. Then it really makes sense that many people fit power commanders to "adjust" the tables.

The right solution I guess would be to have an ECU that always was running in a closed loop with feedback from O2, temp and preassure sensors. Maybe it is just not that simple to keep the Air/fuel mixture right under changing loads. My only experience is with O2 sensors on wood-pellet burners where the load changes very slowly :-)

Well I still have a lot to learn with my first real modern motorcycle. The most powerful processing power on my super tenere was probably the McCoi chain oiler :-)

I also think that is to bad that the instrument don't show more of the sensors values like intake air temperature and coolant temperature.

The closed loop is running at freeway speeds the XT's ECU looks at the intake map pressure/rpm & decides that you are cruising & leans the A/F ratio out to 14.7:1. The narrow band O2 sensors on the XT & most of the other manufactures are just not good enough to adjust all the time they only can work in a very narrow field, you would need a wide band O2 sensor to adjust the A/F ratio if you want the A/F ratio adjusted & trimmed all the time.

Installed the fuel and o2 mods last week. Made the bike some much better to ride. Thanks Kev.

DNA filters going on this week.

Thanks for your feedback.

The O2 and fuel mod arrived just before the weekend - I'm still amazed how fast parcels get around the globe - as long as they don't get stuck in customs.

The O2 was just plug'n'play in less than 15minutes including finding the tools, considering where to place it and taking some photo's :-)

Btw I fitted the O2 controller behind the ECU

The Fuel mod on the other hand was not that easy. It is perfectly straight forward if you are an gynecologist but on my pony the wiring for the temperature sensor is so short that i can only reach it with the tip of two fingers. So I did not dare cut it since i was not sure that i would be able to splice in the fuel mod.

Actually I was not even without issues just getting the top of the air filter. It had to be wrestled out between the abs brake tubes and the wiring. I got the connector of the temperatur sensor but could not work on it. Actually the wiring is so tight i can't even get the sensor out of the airbox before it is disconnected.

I've been working 20 hours this weekend on out local bmx track so haven't had a chance to ride it yest with the O2 mod.

The fuel mod will have to wait until winter and then I'll remove the tank to get room to work.

PS anyone know if it will be possible to obtain a connector similar to the temperature sensor so one could make a plug-in cable instead of cutting the wire ?

I found the easiest way to get at the AIT sensor wiring, without having to remove the tank, yet still have room to work was to feed the sensor through to the right-hand side of the bike. Once you've got it through (just behind the thermostat) there is plenty of space to cut, solder, heatshrink or use the terminal block supplied.

http://i864.photobucket.com/albums/a...ps9ae250df.jpg

Mind you, not so sure about the ABS bike though, never actually seen the plumbing in the flesh - there must be a sh!t load of pipework to get in the way running from the pump/manifold, under the tank and to the front of the bike?

Anyhow, a good opportunity to test the effects of the O2 controller on its own merits for now...

Or join it at the ECU end.