Hi just fitted both kev mods to my ten, the bike has just had its 6000mile service which made quite a difference to the performance, the power hole below 3000rpm was much reduced by the yam dealer, to be fair if i had not already got the kev mods i wouldant have bothered but as I had them i put them on. I put the 02 controller on first and gave the bike a run the first impression was it was a bit lumpier ( you could feel each power stroke of the piston) but the power came in at least 500 rpm earlier so a thumbs up. Next I fitted the DNA stage 2 which consists of the filter plus the very expensive filter cover, (however it gaurantees a good seal.) And then the kev fuel mod I set it to the 5 oclock position and then it was time to give the bike a run. Around town there was not much difference but once i reached the open road I noticed the revs climbed quicker and the bike was definitely more nippy. At first above 3000 rpm I found lumpyness in the power delivery so I pulled over on the moor and reduced the setting on the fuel mod from 5 to the 4 oclock position this smoothed the power as its quite cool tonight about 13 degrees I think the mod was making the fuel too rich on 5. On the way back I noticed the bike held its speed better and i did not have to give it more throttle over the hills. To sum it up, the mods give a wider range of power/torque and the throttle response is more instant. Definitely worth fitting.

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XTz 660 tenere, adventure spec bash plate, main stand, skid marks tall screen, Oxford tail pack 36 litre. Kobra hand guards, Bigger cast footpegs, Zen overland luggage plate, USB power point, iridium spark plug, TKC80 f k60 R tyres, o2 and fuel Kev mods, DNA stage 2 filter. bark buster bar wieghts, Touratec side stand base and GPS mount. Led spot lights

Well gave the bike a long 200 mile run culminating with a 25 mile blast home down the motorway. Today took out the plug to check how the bike is running and found the porcelin of the plug was snow white and the electrode had no deposits on it to speak of, this to me flags up running weak. So i gave the fuel mod a tweak and went back on the motorway after numerous trips up and down and adjustments, i have found if I make the mixture more rich the bike vibrates noticeably if i weaken it it runs better but I am not going weaker than my original setting for peace of mind. So after a good ponder i put the original filter and snorkel back on turned the fuel mod off and went for another ride. The result is hand on heart i cannot tell the difference between the stock and DNA set up. so the fuel mod and filter are not going back on. I am however keeping the co2 mod as that did have a noticeable effect on the flexibility at low rpm. I think the yamaha mechanics have richened the mixture at the last service as the tickover was down to 1200rpm from 1500rpm after the service and the performance was much improved. if i richen the mixture via the kev mod it drops more down to 1050 rpm. I think the apparent increase in performance I thought I had was due to me giving it more stick than usual to see what she would do.

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XTz 660 tenere, adventure spec bash plate, main stand, skid marks tall screen, Oxford tail pack 36 litre. Kobra hand guards, Bigger cast footpegs, Zen overland luggage plate, USB power point, iridium spark plug, TKC80 f k60 R tyres, o2 and fuel Kev mods, DNA stage 2 filter. bark buster bar wieghts, Touratec side stand base and GPS mount. Led spot lights

It seems that some blokes at certain Yamaha dealers can actually adjust the fuel mapping of the bike. Is that not maybe what the guy did who serviced your bike ?
I can't stop enjoying the power and smoothness of my bike. I bought it on 2500km from a friend with a few mods including Scorpion pipes and DNA stage 2 filter and air inlet.
Just today when I told him about your experience with Kev's mod and O2 controller, my friend told me that my bike was mapped by Yamaha to match the DNA filter and specific pipes when he bought it new. I don't know much detail about the tuning (apart from what I've read on the forum), but it makes sense why my bike is so powerful and smooth from below 1500 revs right to redline.
When cold it idles at 1400-1500 rpm but drops to a steady 1200 rpm when hot with enough power to idle in first gear at under 1400 rpm.

[When cold it idles at 1400-1500 rpm but drops to a steady 1200 rpm when hot with enough power to idle in first gear at under 1400 rpm.[/QUOTE]

As above after its 6000 mile service it ticked over at 1200 rpm like a watch and was so smooth from 2000 rpm even in 3rd and 4th obviously you cant give it too much throttle as it will knock hell out of the transmission in such a tall gear. After a couple of PMs with kev and a good look through previouse posts I am reasured that the setting mid way between 4 and 5 oclock is safe for the bike. I also checked the kev mod with a meter to make sure it was working and that the dna filter fitted properly. The kev mod is now back on, adjusted my tickover to 1500 rpm as per yamaha spec, results as per original post more flexible due to o2 mod and more get up and go due to fuel mod, very slightly not as smooth above 4000 rpm as original filter and snorkel .

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XTz 660 tenere, adventure spec bash plate, main stand, skid marks tall screen, Oxford tail pack 36 litre. Kobra hand guards, Bigger cast footpegs, Zen overland luggage plate, USB power point, iridium spark plug, TKC80 f k60 R tyres, o2 and fuel Kev mods, DNA stage 2 filter. bark buster bar wieghts, Touratec side stand base and GPS mount. Led spot lights