Kev O2 controller, my experience
 

Hi all.

I got my Kev O2 controller in the mail the other day.
My 2008 XTR surged/ jerked/ bucked in an annoying way in low and medium revs.
This was so irritating that I reved it a lot and drove it was too fast not to feel the surge.
Mounted the Kev O2 controller and took a 550 km long trip to northern Sweden ( from The capitol Stockholm)
This mod has transformed the bike, almost no surge, the driveability so much better now.
It now drives like a one cylinder bike should, I compare to my previous Yamaha SRX-6, Yamaha XT 600 and Honda XR 600.
I can gear up much sooner with no discomforting jerking motion and my smile when riding is so much greater.
The mod arrived quickly in the mail and was easy to install, (Im no mechanic)
Overall Im very happy with this mod, money well spent.
I highly recommend this mod.

Apart from this mod I use the DNA stage 1 air filter, snorkel in place, everything else is standard.

Big thanks to Kev for making this mod!

Anders

Thanks for your feedback glad you are happy with your results, nice to hear the little black box has made your ride smoother.

:033:

Got my O2 Controller in the mail today. 10-days from Australia to the most northern parts of Sweden on the other side of the globe.
Will install it tomorrow, excited! :)

My O2 controller will hopefully arrive in a couple of days. Shipping from Australia to the middle part of Sweden :)

Fuel economy with Kev O2 controller
 

I have now used the bike with this mod for more than 1200 km.
Still very pleased.
Before the mod was mounted the fuel light came on at around 180 km of riding.
Now with the mod fuel light turns on after 200km of riding.
Same conditions, same highway, same speedregulations, same weather, same single rider with cargo.
To me it seems like I save fuel with this mod.

Im happy

Anders

I'v tried out my controller this weekend aswell.
The bike is a bit stronger on low revs and the surging has been less. Its definitly not completly gone but much better then before.
So Im satisfied with the product.

Thanks for the feedback guys.:bienvenido:

Got my O2 controller today.. Can't wait to install it this weekend :)

Hello!

I installed the O2 controller yesterday and took quite a long ride today with a mate. I have shared feelings about My experience with the O2-controller.

The bike got another motor sound with the O2-controller installed, I can kinda hear that it gets more fuel or something. The sound is sort of more deeper and more rumble. It feels like I can use a higher gear on lower speeds now.. But I have still problem in the 30-50 km/h area (approx. 18-31 mph). It is still quite jerky in those speeds.. 30-40 km/h (18-25 mph) I use the second gear and 40-50 km/h (25-31 mph) I use the Third gear. Sometimes it is good (and it was quite good from time to time before the o2-controller installation) but sometimes it is quite jerky any way.. As Said I can hear that the motor sound is quite different, but it stills surge/jerks a bit in very low speeds..

Anybody that recognize this behavior or is your bike good in the low speed area with the O2-controller installed?

Did you just by the 02 controller and not the Kev fuel mod? If that is the case then I suggest you get that too because that in conjunction with your 02 controller will solve the jerking issues once and for all. Talk to Kev.

I already have a GPR powerjet that is doing the same thing as Kev's fuel mod, I think? Fooling the temp sensor to make the ECU Richten the fuel mix. (I think)

I have k&n open filter, bsm-slipon and the GPR PowerJet. I am planning to replace the powerjet with with a DynoJet Powercommander V.. Do I need a Kev fuel mod anyway?

I seem to recall (from one of your other posts - or maybe it was someone else?) that you weren't sure exactly what the two dials on the GPR Powerjet actually do - is it set up right for your filter and pipe? If you're going to get a PCV anyway, then I'd reserve judgement until you do. The 07/08 ECUs are pretty bad for surging, but an O2 controller/optimizer and a PCV can 99% sort it out.

http://www.xt660.com/showthread.php?t=8546

Your memory are good :) Yes, it was me that wasn't sure about the knobs on the powerjet. The previous owner had it installed and it was a mc company here in Sweden that set it up. I have still not found any instructions for the powerjet, so I have not touched the knobs. But I read that a powerjet or powercommander can't fix the fueling on low revs? (In the closed loop circuit)?

As somebody said earlier in this thread, I also think the bike is a bit stronger on low revs. And I have heard that the XT-bikes are set very lean from stock so I do think it is good to install this O2-controller either way to richen the fuel mix on low revs. Am I right?

You can't do any harm! The O2 controller will definitely have improved the closed loop fuelling. It is just that you are going to have to get the open loop fueling sorted to match the A/F ratio of the O2 controller (13.6:1). Any big difference between the closed loop and open loop fuelling will cause a "step", which contributes significantly to surging.

Without knowing what your GPR device is actually doing, and what A/F ratio it is giving, it's going to be tricky to setup without putting the bike on a dyno. As I said, if you're going to get a PCV, then you may as well get it all sorted at the same time: PC, dyno time and correct maps for your mods.

It will definitely make a difference with a PCV as it will bring the open loop fuelling much more in line with the closed loop. (The GPR unit should be able to do this to a degree - that's is if anyone new what the knobs did! ;) )

Aha, now I understand :) That can absolutely be the problem. As I don't know what the powerjet does, I will buy a Power commander V. I think it fools the ECU via the temp sensor in some way.. Says it is cooler than it's really is or something..

A question about the PCV... I don't think I can dyno bench the bike right away, can I find a suitable map for My bike anywhere? I know that it isn't the optimal solution, but maybe it works quite good until I can bench the bike?

Yes there are "ready made" maps available which will do the job very well. A dyno run and custom map will obviously be even better though. There are lots of maps available to download on XT660.com, tailored to all manner of mods. However, you do need to join the supporters scheme (�10) to gain access to them (and lots of other useful technical stuff and 1:1 support from Kev). To join click on the link in my signature.

I will be a supporter right away! :)
Is it for 1 year or for life? Does it cost 10 pound per year and do I have to Renew it in some way or does it just expire after a year?

It is a voluntary membership that only costs a tenner per year and there are no obligations to re-subscribe once the term expires, you get a reminder from the forum software a few days before the end of your year subscription, asking you if you wish to renew or not. If you ignore it or do nothing, your subs will naturally expire and you will not be bothered again by the software or anyone else, rest assured no money be taken from any account without your consent because this system only allows PayPal payments and as you know you always need to authorize these before PayPal pays anyone.

Cheers

Thank you for the information. I will be a supporter during the day today. Am on a train at the moment with bad mobile coverage. Don't wan't to deal with creditcard payments when I can get out of coverage :)

Other things that cause surging are worn chain & sprockets, chain to loose not adjusted correctly & the most common one is the rear sprocket holder damper rubber with free play.

1/ Make 100% there is no free play in your rear sprocket holder, grab the rear sprocket & try & move it forwards & backwards there should be no free play. If there is free play replace the rubbers or carry out my rear sprocket rubber mod.

2/ Make sure your chain does not have tight spots, lift the rear wheel in the air supporting the bike with a stand or box so you can spin the rear wheel freely, turn the rear wheel slowly while pushing the underside of the chain upwards towards the swinging arm the chain should not change it's length or try & push your hand downwards, if your hand is forced downwards & upwards when turning the rear wheel your chain has tight spots & can make the bike feel like it is surging.

3/ If your bike chain has no tight spots & is adjusted to loose the bike will feel like it is surging.

Thank you, will do the tests on my bike :)

Well Kev, you were right I think.. I had quite alot free play when I tried to move the rear sprocket forward and backwards.. The drive line are fine. Will fix the rubbers.. Is it ok to ride the bike with bad rubbers?

It is OK to ride with worn rubbers but not with rubbers that have broken up & they do break up over time, so check them as soon a possible the free play will make the bike feel like it is surging because of the free play.

Nice to see so much life in this thread.

Im including new rubbers in my rear sprocket holder when doing service on the bike this autumn.
There is lots of play when moving the rear sprocket, I bet these rubbers have never been changed, bike is a 2008 with 19000km on it.

Anders

I will do that too :)
My bike is a 2007 and (almost) 12000km. Not so much for a 2007 but I don't think my have been changed either. Some say that they work for like 5000km, that is not very much.. I don't think it is that easy to check the condition on them, because you need to remove the whole wheel and disassemle the rear sprocket and sprocket holder to actually see the rubbers..

Anybody who knows where to buy the rubbers in Sweden?

One more stupid question... You said in an earlier post that I should try to move the rear sprocket forward and backwards. In which direction? :p
I pushed it towards and backwards from the wheel and i had some free play.. I did not push it in the direction it moves.. I think I did wrong, didn't I?

End of stupid questions ;)

Tar det p� svenska, du ska ta tag i d�cket med en hand och med andra handen f�rs�ker du rucka drevet i sin rotationsriktning b�de fram�t och bak�t. Det ska inte glappa n�got.

My cruchdrive rubbers were bad with only 1200km on the gauge. I didnt have any real freeplay but with handforce i could move the spocket about 3-5mm in its rotating direction compressing the rubbers. Made the mod and its alot better now but I will buy new rubbers and replace them anyway.

If you have rotational movement (turn the sprocket some way before the wheel moves and takes up drive) then the cush rubbers are worn. If you have lateral movement (the sprocket can be pushed/pulled on opposite sides and waggles about on the axle) then the sprocket carrier bearing is worn.

I have not tried to in the rotational movement yet.. My bike is in another town atm.. But yes I was able to move the sprocket pushed/pulled on opposite sides and waggles about on the axle..
How hard (and expensive) is it to fix the sprocket carrier bearing?

It's one of the easier bearings to do, mainly because it isn't attached to anything big and unwieldy, plus it seems to slide out without too much bother. Drive it out, then ideally press (but you can drive) a new one in. The bearing is about �15.

Nice there, thank you ! :)
Can the bearing cause surging as well?

Will do some maintenance on my bike now. The season is almost over here in Sweden..

Is it this bearing I need?
http://www.off-the-road.de/en/XT-660...ea9c3e2b0306c3

(Bearing, rear, sprocket cusch drive)

Yes.