if there is a bottom hole on the pedal it will give you more leverage. Does it look like your pads are wearing evenly? If not your caliper hanger might be welded out of square or bent. In that case new pads will make the problem worse. Is your disk the thin steel kind or vented? it might be getting over heated. That will give you brake fade after a few laps. brake fluid should be either mineral oil (dot3) or synthetic (dot5), make sure you know which before you melt your seals. Usually most take dot3. Bleed your brakes after every track day enough to get fresh fluid through the whole system.
Hope that helps,
FAA certified jet engine and aircraft technician,
Nicholson Speedway class champion 2001,
Yamaha KT100 Service Center,
41 years karting experience