I see no one has replied 2 u so here goes..  I purchased an 06 leftover brand new from a loacl dealwer here in WNY..Had mainly polaris's in the past but a guy I ride with has a 05 F-7 and if he can't break it than I certainly cannot break mine, To get to the point because of poor snow conditions I only was able to get 400 miles on this past year. Didnot have any issues with it but in reality most of the modern day sl;eds  can withstand anything I may have for them with that one exception of a ttree once in awhile. Right from the start I really liked the sled.  I had a ProX 800 before this one and it really feels the same. Both handle the same and ride the same. I had the sup set at full soft on the F-7 and the Prox was set up in the "old man mode". I am 51 and half beat up..Like other sleds in the past I had I could not leave it alone and purchased the Bikeman pipe stealth pipe along with the clutch kit that goes with it..  I am very satisfied with the combo so far..  The set up works cause I can  smoke the stock o05..  Have not yet run much of anything else.. THe 05 has run with just about evrything else with good results.. I run with my friends new 08 Drgaon 700 when they were both new and whoever got the best lane won the race. Stock for stock they were dead nuts. In the trail I thought mine was better felt lighter and turned quicker.. Turning now that is another subject.  Turning radius sucks on them so give yourself a wide birth when doing so.  An average 3 wide trail just get used to look for a field or start pumping weights cause thats what you have to do.. Arctic claims they will start on the third pull and it always does sometimes evan the first when cold..  Also have a friend with the snopro and thats equally as nice.  Only bad thing about them is the track cause odf the lug height does tend to slow your top end down by 3mph or so but they do launch nice. Mine is the standard,,pickel green.. good luck

I am surprised more people have not answered you.. Again I only have  350 miles on mine..  No Problems with the DD so far but I donot wish to jinx myself.  I have heard some of the 06's have an issue with the  seal put in backwards so that is a big fix so watch for a puddle of oil underneath the sled..  I again have not had problems so far.. I do miss the reverse.  Sometimes you can hear the dd working like a street car rear end sounds kinda cool actually.My friend has almost 2000 miles on his w/o problems that was an 05.. You might as well throw those runners in the garbage cause they last about one ride maybe two but they are bad.  We ran out of time and snow I wanted to hit Canadian highways for a week but didnot find the time.First sled I have been on and go fast right away at least fast for me..Don't touch the engine maybe throw the bikeman stuff on but thats it..  They are real hard to improve on unless you are a sharp with the sleds.  Think snow.............................

Sorry didnot get back to you sooner.  On the F-7's they are fuel injected so no rejetting is done. Some guys like the boondocker system which you can lean down or richen manuely ( I believe).  Thats ok for them I guess but it's just another thing that I would screw up.  Did I turn the knob the wrong way or not?...lol Dynotech research has done gobs of tests on the F-7 and differant mods.. Some guys run the timing keys and others but again leaned it down then I don't want to know.Really for thier size they are really overachievers and it's hard for me to believe they would dump that engine,. I should have bouight two..