Nice one Nic thanks for your feedback, we now have a comparison against the Regulator/Modulator Verse my my O2 controller mod.

As mentioned in our Email my 2012 O2 eliminator works slightly differently to the O2 regulator, their signal generator emits a fixed pulsed wave signal, my O2 eliminator uses the O2's sensor voltage & alters the output voltage from the sensor in a square wave, the mod then corrects the input voltage & sends it to the ECU according to the A/F ratio in the closed loop, Dyno jets Regulator is a fixed input signal & is not adjusted by the A/F ratio in the closed loop.

Dyno Jets latest O2 Optimizer works on a similar principle as my O2 controller.

Well Kev, I have now put over 1000km with your O2 controller fitted and all is great.
I have ridden in many different conditions and on many different types of roads from dirt to open country and twisties (also towns and traffic).

You can still find a little surging if you go looking for it, I find it in the lower gears at lower speed with mid rpm (2nd or 3rd around 30-40 ish kph) but it is not to bad (by the way I only notice this in town or at some road works with traffic). There could be other factors that make it seem worse than it is, like drive chain slack :smirk:.

As I said, if you go looking for it you will find it but on the whole it is so much of an improvement (90%) over standard I cannot fault it at all.

This is in my opinion the best mod you can do to these bikes and also the best value for money mod you can do.

Well done Kev and a big thank you for this mod, it has made this bike even more of a pleasure to ride, cheers.

Shane

Thanks for your feedback Shane.

The O2 Controller is only part of the equasion to surging but is one of the most important ones to reducing the surging. A good fuel map for open loop tuning + a good chain & sprockest correctly adjusted & no free play in the rear sprocket holder rubbers. Do all the above & your bike bike will ride like a dream.

I would also add my twist grip mod to the list for better small throttle opening control.

http://www.xt660.com/showthread.php?p=154983#post154983

O2 Controller now on Ebay. If bougth via PM I will post world Wide Australian AUD$95.00 + postage cost to your country.

Hope you guys don't mind me using your feedback, it does help get exposure to the forum & my mods.

http://www.ebay.com.au/itm/Yamaha-XT660X-XT660R-XT660Z-XTX-XTR-XTZ-O2-Controller-/130785899498?pt=AU_Motorcycle_Parts_Accessories&ha sh=item1e737273ea

Just got my bike remapped after fitting Kevs new eliminator mod.

It runs so much smoother now, the a/f is 3.2-3.6 over the whole range. With the dynojet modulator it had a dead point at around 4500-5500rpm, that is finally gone now.

Unfortunately I havent been able to enjoy my bike as much as i wanted to since the bike got fixed the last couple of days due to rain....

Once again i can really recommend people to get one of these mods with a powercommander.

Thanks for the feedback Nic you are the second person to Dyno tune your bike with a Power Commander + my 2012 O2 controller mod, at least we can say it works well enough to fool the Dynos computerized software & you can build a stable fuel map with it connected, as mentioned in our Emails please can you send me a copy of your PC map.

I am very happy with the results of the O2 controller, the funny thing is I new how to make this mod back in 2008 but did not pursue it as I wanted to turn the O2 Closed loop off & was not interested in controlling the closed loop so really never finished & tested it completely. Then the KTM boys were asking how to control their O2 closed loop circuits & the mod came live again.

Same mod now applied to 3 different motorcycle manufactures. :Tennis_ABHMXO:

We will see how long it takes for someone to copy it.:lurk:

I still have 2 X O2 controllers in stock if anyone wants one, or off Ebay. http://www.ebay.com.au/itm/Yamaha-XT660X-XT660R-XT660Z-XTX-XTR-XTZ-O2-Controller-/130785899498?pt=AU_Motorcycle_Parts_Accessories&ha sh=item1e737273ea

I bought one and on a completely stock 08 (motor wise) she's made it a lot nicer to ride. Hardly any surging at all, made me realise how much I had been riding around the problem by staying out of the midrange at low throttle openings.

Thanks for your feedback, it is great to see the O2 Controller improves the ride on a completely standard XT.

I spent a few hours last weekend & 10 hours today making up the next batch of O2 Controllers & I still have an hour or two left. My supplier of the small boxes ran out of the original size boxes so this next batch will have a slightly different box with the exact same internals. The supplier of the OEM connectors has also run out of stock & the connectors are on back order for me as I bought his entire stock & have used all of them on this latest batch, I am not sure when they will have stock again they have been on back order for 3 weeks so far. So those who snooze will have to wait a bit as I have no time line for the next batch.

They can be bought via PM or off Ebay.

http://www.ebay.com.au/itm/130780380438?ssPageName=STRK:MESELX:IT&_trksid=p39 84.m1555.l2649

http://i201.photobucket.com/albums/a...ps47146c66.jpg

Done 600 km with O2 Controller
 

Just reporting back that the most fun I've had on my bike has been since installing Kev's O2 Controller. Such an easy fix for this long term issue. I totally recommend it.

One related thing, Kev... I've been reading back treads of the forum and have been surprised by the few people who actually say lowering their CO1 level by 10 from standard actually improved their ride. I wonder whether by lowering their CO1 levels (and therefore leaning the A/F further in open loop)they were actually better matching the low rev open loop to the standard lean closed loop - making it feel like the bike is smoother because the switch between open and closed loop wasn't so dramatic?

Of course, that would mean the bike is still running too lean overall and much better performance can be achieved by fixing the closed loop with the O2 controller and upping the CO1...
Anyway people, get a O2 controller and see for yourself!

Nice one Dan.

Running a to lean or to rich mixture can make these XT's surge at part throttle. I would say your thinking is spot on to an extent but you will loose some Torque & HP with a lean mixture.

CO1 can only adjust the fuel mixture up to around 2% throttle openings or there abouts which I call part throttle openings, after that the ECU runs on a map & the CO1 adjustment make no difference to the A/F ratio at all.

Any number over a TPS reading of 18 the ECU will run on the pre- programmed Yamaha map, in the early days before O2 sensors I used to say to riders they should adjust their TPS to around 16 so we can adjust the part throttle opening A/F ratio with the CO1 adjustment.