2008 Outlaw 525s shifting problems

[wyo1bowhunter]

I have a 2008 525s with air intake, full fmf exhaust, jetted and it runs great! My only problem with this bike is it will false shift from first to second quite frequently, especially during races at the dunes. Most of the time you have to shift it twice to get it into second gear, then shifts fine from there on. Have taken it to the dealer and it doesnt seem to do it as much with dirt tires on and they say they cant make it do it so there is nothing wrong- now my warranty is up its my problem! Has anybody else had this problem and what are my options to possibly fix it? ANY help would be appreciated!!!!!