A brief update on my 500.
As a starting point, I love the chassis and the power. From a performance standpoint, it works really well out of the box, I haven't changed a thing, the only thing I can see myself doing is adding a bit of oil to the forks to help hold them up deep in the stroke. They are great on trail chop but a little soft when whoops come around.
However, I'm still getting lousy mileage. Out dry at 53 miles last week. So, I called KTM of Aspen (best shop in the world) and their analysis, based on extensive experimentation, is as follows.
1) None of the sensors can cause bad mileage. They will throw lights, but the bike will run just the same or not at all.
2) The TPS is the only one that can create a strange running condition- if it is way far out of whack, the bike will hesitate and stumble. But, that's at one extreme of the range- with it anywhere in the middle the bikes seem to run fine.
3) The fuel injectors are inconsistent. To get the smaller bikes to start easily at elevation, they have to mess with the mapping, and they found they required different settings on different specimens of the same model. They started swapping parts and found that the fuel injector is the cause.
So, the operating theory is that my fuel injector was sticking open, dribbling fuel when it should not have been, and thus giving me terrible mileage. I swapped it for the one I'd had in the airbox, but weather and work have prevented me riding it.
I think the useful takeaway point for anyone out there trying to tune one of these, is that the sensors are not likely the culprit.
News to follow when I get to ride it.