I have a 97 sportsman 500 and I have to pump the brakes on the handlebars to get them to work good usually twice is good. I have checked the fluid and it is full I replaced all the pads last year and didn't ride it alot don't know what to do next.

 

just a guess, but if you havent got any air in the system, sounds like the master cyclinder is a little weak and dont hold the pressure good. imo.