Baby steps.
I have turned the 2007 YZ450F I traded into a trail bike, we went through the carb since the former owner had stated he jetted it for the Bend OR area's cold dry conditions. I don't know their elevation range, but I'm sure over 3K under 10K.
He had it rich since most of the time it was wfo, he's a fast guy! 2Moto was this bikes conversion, I would assume any other brand kit would require similar changes. Test riding the bike on wheels in my neighborhood it felt slugish, here's what I found, 180 main, and 48 pilot, needle fourth clip down, aftermarket FMF 4.1 Powerbomb free flowing non USFS full exhaust, pod filter deleting the air box, and original 13t front sprocket. Stock jetting has been replaced, 160 main, and 45 pilot, needle third clip down, same exhaust.
Anyone interested in working a trade for a stock or USFS exhaust?
Your choice, the KTM505 should be using the same Keihn carb, I would run it stock first and get a feel for where the 505 is at. Don't work it too hard by planning a full day ride with the Twoskis, stay close to the truck maybe even prepare for jetting/carb changes on the snow. At least being a fourstroke you can run it lean and get it hot for a while figuring it out.
If it is the Keihn, get four longer bowl screws first, the stupid allen's that come stock don't even protrude through the threads on the carb body and strip easily.
I know 2Moto had a 505 a few years ago but that was a demo machine going on short runs, I have know idea if they changed it or any others during long term testing. Most of the Explorer reps I am aware of don't even have that much expertise on bikes, let alone their kits, what they do know is where they ride not everybody elses terrain. Untill guys get some time on these or all bikes go to EFI I would'nt trust anybodys answer since as you learn to ride you will get more aggressive. I wish these guys would get interested in the one ski craze, could solve alot of time with their expertise.
http://www.jdjetting.com/
My old KTM300 was rich as a trail bike and back then it seemed KTM was doing it on purpose, probably still that way. Bringing the YZ back to stock specs for dirt duty seemed spot on for the foothills 1,000'+ so I'm sure it could go leaner as I climbed. The only time I've ever richened a bike for elevation was for long term wide open conditions to solve detonation at a dessert race, usually just raise the needle, or up a few sizes on the pilot cause a new pipe was installed. The jetting I removed shocked me, if you tried to run that much increase on the dirt singletrack at any elevation it would run like a richly mixed twostroke. Only the real fast guys get away with that and not foul a plug, they are the only ones WFO!:face-icon-small-hap
