Nappy

I tried to search, but found nothing. I am gonna buy my roomates 01 f4i. He just put on a brand new Powers cage,spools, and -1+10 gearing. He looped a wheelie before buying all this stuff and now decides he doesn'e want to stunt anymore. He is gonna give it to me for 3500 bucks. Only problem with the bike is second gear always slips. as soon as I hit the throttle it goes back to neutral. I was wondering how hard it is to replace that gear, or how much a dealership has charged you guys if any of you have had it done. Its clean titled and everything. I hope I am getting a good deal. That gear is the only thing I am worried about. Full fairings are still on and good too if that helps decide if it is a good deal.