The 2007/08 XT has a few limitations when it comes to fuel management, it is delivered with the 10-ECU and an O2 sensor. A device such as a Power Commander is therefore at current not an option to fine tune this setup. The surging on my bike (OZ release) was quite substantial to that extend that my local bike shop had a few non fruiting goes at it and concluded in replacing the ECU with the one built into the 09 model ending in 11.

The setup to this point included a stage 1/2 air intake modification with the snorkel used as a door stop, and some mucking around with the CO setting.

After the ECU swap over and a few minor CO adjustments the surging was better but still noticeable across the whole lower rev range. Another interesting behavior was at around 50km/h cruising speed a constant switch (on/off) would become audible and the bike would enter super surge mode. I decided to live with this (and only ever ride the bike in the red area) since the mechanics have tried whatever they can do to rectify this issue and the next step would have been to cut my losses and hand it back.

After this decision I moved on and replaced the exhaust with a 2 into 1 from MM ending in a Scorpion muffler. Again not as straight forward as I hoped to get it to fit to my XTX model (seems to be a bolt on exercise on XTR). I had to get a local exhaust specialist to cut, bend and weld a few things to get the system to fit properly and clear every obstacle in the way.

Now here is where it gets interesting, the new exhaust seems to have rectified a lot of the above issues and surging has diminished almost completely which sort of indicates that the factory exhausts are part of this whole problem. Another nice side effect is that the bike now sounds more like the old ones used to, you can hear the single cylinder again - and yes it is quite loud, which I consider important in daily commutes to get the attention of the car drivers.

I like the bike a lot now, it looks understated and lighter without the pipes under the motor, still a bit on the heavy side and therefore underpowered but other aspects such as handling (not talking race track stuff) is great, it's very easy to ride and supposedly cheap to keep going in the long run (we will see) all of which are important aspects when I choose this bike for an everyday bike.