Kev's O2 Controller on the T�n�r�
 

Fitted Kev�s latest O2 controller to the T�n�r� (when it was snowing a month ago) and have finally got a good few hundred miles riding in to evaluate things.

The bike already has the fuelling mod (set at 6) and DNA stage 2, which improved the flexibility of the motor hugely, broadening the spread of power, particularly in the lower revs on a wide throttle.


So what difference does the fitting the O2 controller on the Z (which doesn�t really suffer from the same surging issues of the R/X)? Well actually, quite a big difference � I was pleasantly surprised to say the least.

Most noticeable is the throttle response; snapping the throttle wide open (from a closed or small opening) at any speed is noticeably more smooth, linear and productive in terms of forward motion! Second is the fact it will now sit at a slow, leisurely cruise in traffic at say 2000-2500rpm without any sign of hunting � you can set the throttle position and the bike�s engine and road speed remain utterly constant. Fuel consumption, over just shy of 300 miles, appears to be identical to that before fitting the O2 controller (57mpg).

All in all, I�m well chuffed with the outcome (thanks Kev) � the T�n�r� is happier, both in traffic and out on the open road. Thoroughly recommend considering this mod whether you�re running a Kev mod or PC; more closely matched closed loop and open loop fuelling really does make a big difference.

Friend who scribbles for a well-known bike mag had a ride yesterday and said (I quote) � �That�s ****ing flexible for a single and keen to pick up off the throttle too � I really like it.�

Thanks for your detailed report, controlling both the closed & open loop circuits makes a big difference to the XT's ride no matter if the bike is completely standard or has filters pipes ETC.

Does that statement hold true with a PCV fitted Kev?

(Katy is due a tweak, been a while since I treated her,,, and me!)

Please tell me more, I love my XTX with the Kev fuel mod fitted so how much is the O2 mod???

I'll can have a shot at answering that...

Whether you've got a PCIII, PCV, Kev Mod, Nitro-X (or nothing at all) the air/fuel ratio will be stuck at 14.7:1 in the closed loop (unless of course you've already got the Dyjet O2 eliminator fitted). The problem is when you've sorted out the open loop fuelling with your PCV map to get a more respectable 13.2-13.6:1 there is a massive step in the mixture when the change occurs between closed and open loop; this is where the problems lie. By fitting Kev's O2 controller, which permanently fixes the ratio at 13.6:1, this step in fuel/air ratio between open and closed loops disappears, smoothing things out greatly.

It will definitely make a difference with a PCV as it will bring the closed loop fuelling much more in line with you map stored in the PCV.

Ta muchly.

Now, having both DNA S2, PC-V and the MTC single can, the bike runs very well from low revs. The MTC improves the low speed pickup immensely and allows better low rev performance.

It's probably worth my while giving this mod a whirl, just to compare results if nothing else.

Works perfectly with a PCV, been tested by 5 different guys on different Dyno's.:walk1:

Spot on I could have not explained it better myself.:laughing7:

That is precisely why I decided to do the O2 mod - as much out of curiosity as anything else.

Just waiting for the postman now.......:thumbleweed:

On it's way in 12 hours Oz time.

Kev, where can I buy this O2 mod of yours. Got a link?

They can be bought off Ebay or directly from me via PM, payment via PayPal.

http://www.ebay.com.au/itm/Yamaha-XT660X-XT660R-XT660Z-XTX-XTR-XTZ-O2-Controller-/130858468499?pt=AU_Motorcycle_Parts_Accessories&ha sh=item1e77c5c493

3000 Mile Update
 

Covered a further 3000 miles with the O2 controller fitted, so I thought it might be a good idea to give a quick update on the XTZ's performance and general running.

Firstly, the bike appears to be more economical, giving at least an additional 20 miles before the F-Trip starts flashing and is returning just over 60mpg (4.7l/100Km), whereas it used to be a little over 56.5mpg (5.0l/100Km). I believe this can be attributed to the motor pulling more cleanly from low down, as low as 1800rpm in fact, allowing for earlier up-changes and smoother throttle control; yet I’m not (as far as I’m aware) riding any slower.

The second big plus is that in heavy traffic and particularly riding slow trails the bike will spin up from tick-over with little need to ride the clutch, which makes life a whole lot easier and more enjoyable. Having had a 14T front sprocket in the past to try and achieve a smoother roll on from tick-over and snappier acceleration, I can safely say the O2 controller (in conjunction with a fuelling device) and a 15T sprocket achieves the same results, but without the disadvantages of lower cruising speed and accelerated front sprocket wear.

The O2 controller is a thoroughly worthwhile and very cost-effective mod for the T�n�r� - there is much more to it than just being yet another cure for surging R/X models.

Thank you for all the explanations. I'm thinking on adding the PCIII and DNA Stage 3 filters, plus Akropovic pipes, so it's always good to know these details. :038:

I'm just confused on the mileage part. :017:
Adding these mods will in fact improve fuel efficiency even further? I'm doing 4,5 L / 100 Km, which I already find to be very good.

I don't think you can really compare one person's fuel economy and another's, even if the bike is the same, we all ride differently. I've just made a direct comparisson before and after fitting the O2 controller - same bike, same rider, same roads etc. The difference in my economy is down to a subconscious change in riding style as I've adapted to the different fuelling characteristics: Before I was generally riding between 3000rpm and 6000rpm; I can now achieve the same road speeds using 2000rpm to 5000rpm. Basically you're getting the same power but at a slightly reduced throttle opening.

Of course you could use that extra engine efficiency to go faster than you were before, and then your fuel economy would get worse! ;)

To feel the full benefit of any fuelling mods (PC, filters etc.) throughout the whole rev range you are still going to need to control the closed loop with some form of O2 controller, either Kev's or Dynojet's.

TBH I've got Akros and they made no difference whatsoever to the engine's performance, they're just lighter and sound better than stock pipes!

The closed loop circuit trys to keep the A/F ratio at 14.7:1 this is very lean & reduces the Torque & HP output of the motor & is not the most fuel effecient A/F ratio, 13.6:1 has been proven to have the best fuel economy fuel A/F ratio to HP/Torque.

With a O2 controller fitted it trys to keep the A/F ratio around 13.6:1 good fuel economy + extra HP/Torque compared to an emission control A/F ratio of 14.7:1.

Yeah, I'm thinking in getting this one.
I'm interested on the Akros specially for the 2 Kg weight removal. It also helps in performance, doesn't it?

Adding the DNA Stage 3 and the PC + O2 will force me to go to the Dyno. I wonder if I have to go to the Dyno again after adding the Akros on a later date. Do you have an idea on this part please?

The pipes really won't make that much difference to the fuelling. You could go back to the dyno for a fresh map, but it wouldn't be absolutely necessary. The filters make the biggest difference and will be the thing that benefits most from dyno time.

That's all I needed to ear. Thank you. :thumbsup:

Above o2 link is dead
 

Want to purchase the o2 mod. Could someone give a link to somewhere i can purchase it. Does it come with instructions.

Send Kev a PM or buy on eBay...

http://www.ebay.com.au/itm/Yamaha-XT...item1e77c5c493

Yes

I have a 6 X O2 controllers left as I have sold more than expected, with the OEM connectors on back order again so not sure when the next batch will be ready last time it was 2 months before I got the back order connectors.

Kev's mods

http://www.xt660.com/showthread.php?t=20592

So, let me see if I got this:

O2 eliminator required to fix closed loop so the jump in AF ratio between closed and open loop is not so big.
On that note closed/open loop refers to idle throttle/open throttle.. ?

Moving on - Kev's mod fixes the open loop AF ratio so that you can turn the knob to experiment and find where you feel the bike running better (as in stronger or smoother?)

And may I ask - where have you all fitted it? I've got the ABS version there is *no space* under the seat to speak of. Will I need to dismount half the bike to fit it?

Yes. It fixes the AF ratio to 13.6:1 instead of 14.7:1

Sort of, but it's a bit more complex than that.

Closed loop is where the O2 sensor is feeding information back to the ECU about air/fuel ratio and fixing it to 14.7:1 - this happens at idle, small throttle openings and constant throttle when cruising below 3500(ish)rpm. It will be fixed at 14.7:1 regardless of what any fuelling device is set at.

In the open loop the information from the O2 sensor is not used to correct the air/fuel ratio (a fuelling devise will be able to control the air/fuel ratio in this state and get it down to 13.6:1) - the open loop operates at large throttle openings, high revs and while accellerating.

Yes.

I fitted the O2 controller on the flat underside of the tank behind the left hand grey panel with a sticky pad. The Kev mod is quite small and I dare say could be sqeezed under the seat, but you can lengthen the two wires very easily and mount it practically anywhere. Some folk have mounted it by the dash so it can be adjusted on the move. You'll be able to get it in somewhere for sure.

The break in point is just above the engine on the left side of the bike (as you sit on it) I have the O2 tuner cable tied to the long bolt that holds the tank on. The red light puts sort of a red glow all over the engine in the dark, looks weird!

It doesn't go under your seat, not sure the cables would reach. Takes about 5 minutes to fit from start to finish, and you can remove it just as quick if you want/need to.

Yeah, I first fired mine up (with the O2 controller fitted) at night and I thought something had caught fire under the tank!:incon_aargh[1]:

Great explanation guys. I've been hanging around this forum for a couple of years now seeing "closed loop" this and "open loop" that but never really gotten a sense of what it is. Someone should sticky it :p

The XT's fuel injection is explaned in detail in the ASK Kev section.:happy:

Some reading can be done in this thread, http://www.xt660.com/showthread.php?t=14746&page=19

...never was there a better reason to join the XT Supporter's Scheme!

Wow Kev, can't thank you enough!! Got the O2 mod fitted in a few minutes and took the Ten for a 300km blast through the twistes around Jarrahdale in WA. What a different bike!
At idle to mid throttle it's like my old TTR, smooth and predictable but with torque on tap!
Can't believe how nice roundabouts and traffic driving are now, no surging or sharp throttle snaps... But the response from 2000rpm up is awesome on the open road, just twist and go, smooth all the way.
Again, thanks heaps.
Matt

Thanks for your feedback Matt, the O2 Controller mod does make a nice change to the bike.

I have only 1 X O2 controller left, not sure when my supplier will have the connectors for me they have been on order for a few weeks now, hope it is not much longer.:dontknow:

Well lucky I got in when I did!! It's funny, loved the bike before and didn't know it could be better until reading all the reports and thought I'd give it a shot! Wow couldn't imagine not having it now!
Matt

I can confirm this for Standard Tenere ABS.

The OEM O2 controller Connectors have just landed in Australia should have then early next week so we will have plenty O2 Controller stock again. :sbike: I have also just placed another bulk order so I don't run out of connectors again.

Just got the O2 mod fitted on my XT660Z this weekend after receiving it last week. Like others on here, I didn't think I needed it for my tenere but after reading what a few people have said I have to agree!!

With the stage 2 and Kev fuel mod, the O2 mod makes this bike smooth. It really makes a difference in the low down revs.

Love it. Cheers Kev!!

Thanks for your feedback.:icon_jokercolor: I spent 9 hours yesterday making up O2 controllers.

Got some kits on EBay right now. http://www.ebay.com.au/sch/7416kevinh/m.html?item=130929079513&ssPageName=STRK%3AMESELX% 3AIT&rt=nc&_trksid=p2047675.l2562

Hi Kev,
just ordered one on Ebay. I am looking forward to apply it to the bike:).

Cheers,
Marcus

Thanks mate I will process the sale when I get home tonight & Email you all the fitting instructions.:bounce016:

Fitted my stage 3 and Kev mod + O2 controller. It sure it's much noisier now and it sure does have some more power into it.
How one knows if the mixture is too rich or too lean?