What service did you have done to the bike? Did they change the coolant? Since you say the fan kicks on, it is probably air in the line that needs to be removed. If you have not I would do like shenoyp suggested and replace the stock fan with a Muzzy fan. And welcome.
I doubt you need a MUZZY fan, I would figure out what the issue is and fix it, not bandaid it with something else... It is obviously not working right..
Check the coolant level... If you have too much anti-freeze per water mix, it will run hot... Make sure you have a 70% water and 30% anti-freeze mix...
If this isn't it, maybe its the thermostat...
What mods do you have? What service was done to it...? Always ask yourself "what has changed..." Obviously it was just worked on and I am betting something there caused this...
You should take it back to the shop you had it worked on and tell them it is now over heating since they worked on it. They will at lest tell you what the issue is, I am sure...