02 thingy for the 07-09 model
 

saw this on ebay, im not interested in the claim of more power.. but i was wondering if this is the sort of thing the newer models need to up the fuel as the Kev mod wont work....

http://cgi.ebay.co.uk/15HP-O2-SENSOR...3A1%7C294%3A50

It is a simple voltage divider made up of 2 resistors, made one, tried one & it did not work. You can make one for about 10P.

I know you know this info, so this is for the other readers. The XT is a bit more complicated then the standard fuel injection motor with O2 sensor.

When you unplug the O2 sensor on the XT it runs to rich around 11:1 we are looking for 13:1, my fuel mod can only make the fuelling richer not leaner, this is the problem I have had when you just unplug the O2 sensor.

I have made many different types of O2 Eliminators, signal replicators voltage dividers & can not get the fuelling spot on the 07 to 09 models.

The problem is the AIS is also thrown into the equation with the A/F ratio, when the ECU sees you on the cruise it opens the AIS valve the O2 sensor sees this as a lean mixture & knows you are on the cruise so compensates the A/F ratio for the AIS being open & sets the A/F ratio to 14;1, the problem I have I copy the O2 signal reading with a fixed signal & send it to the ECU, when the ECU sees you on the cruise it opens the AIS & is now looking at the A/F ratio + the extra air it thinks it's getting & sees my reading & thinks it's running rich so leans the ECU out.

When you use a voltage divider it does helps but the Yamaha fuel map is wrong in the closed loop circuit so you still have the surge. The voltage divider divides the voltage sent from the O2 sensor to the ECU by reducing the voltage by -0.1 to -0.3 volts from the orginal voltage depending on the resistors used, the ECU sees the new voltage signal as a lean signal so richens up the mixture, this is good but the Yamaha fuel map is not right so the surge is still there. In the closed loop circuit the A/F ratio is to rich & to lean over the rpm range, we need a power commander to adjust the A/F ratio across the whole rev range in both the open & closed loop circuits.

There are many ways to make the 07 to 09 have better fuelling, but I do not know of a perfect solution as yet. I have high hopes on the PCV with Auto tune, we will have to wait & see when someone fits one.

Kev, i was hoping you would answer this.... i would love the PC with auto tune but that is one heavy price.... shame

It sure is. If I get another XT I will have to get one.

i know.... get one anyway, test it on someone elses bike, im sure they wont mind.... then make a cheaper one... sorted.

Hi Kev. I have been looking for information for Power Commander V with autotune, but I just found it for XT 09 models. Do you think it will work at 07-08 models (with sonda lambda)? I don�t understand why it is selling only PCIII for 04-08 models if 07-08 models has got the sonda, and PCV with O2 sensor is only selling for XT 09 models if it has got sonda landa too. Sorry for my english and thanks again

I can not see why I PCV with Auto tune would not work on the 07/08 model XT660X/R. I know for fact that the 07 XT runs fine with the 09 XT ECU, therefore the PCV would work on 07/08 models.

Do you say that if I use a 09 XT ECU in my XTX 08 it will ride fine without surges?? I thought it happens using the 06 ECU in a 08model and using a kev mod or a power commander III.
PCV It is only selling for XT 09 models at webs (I think they have not maps for 07-08 models, based at your explication).
I would like to buy one PCV to my XT 08 to cure all the surges, but not now (it is so expensive yet).
If anybody try a PCV with autotune in a XT08 model and works fine, I would like to advise me.
Thanks again

The 09 XT660X/R models still have a surge, even though the 09 model has a different firmware version the the 07/08 models, what I was stating is the 07/08/09 ECU's are all interchangeable, so the PCV should work on a 07/08 Model.

You can not fit a 06 ECU to a 08 model unless you change the bikes whole wiring loom to a 06 model, the ECU's have different pin locations & the 08 ECU has more pins with a different ECU plug.

http://www.xt660.com/showthread.php?t=8478

The best way to tune your bike correctly is on a dyno with Tune Link software & the map is made for your bike, no matter if you are using a PCIII or PCV. Freez has already tunned a raptor 700 with PCV & Auto tune & has recommended that it is set on the duno first to get a base map. Once there are base maps out there for the XT660 we can start the Auto tune from that base map.

Hi again kev!
I have seen at some webs that PCV with autotune is selling but it says than only for 2009 models!!
You said that is exactly the same machine but different firmware (I hope have same connections too).
I am interested at buy one for my bike but afraid for the surges don�t be cured definetly.
Do you know any XT 08 with PCV that cure the surges definetly?? Thanks