can anyone help speedo getting hot

[bigtrev]

Right i bought a second hand vortex r10 pro of ebay works fine turned all timing off drive it around on the patio with in less than a min its really hot 50c bought a fan for it plugged it in it doesnt work or does fan come on when it gets hot. fan works brand new and tested new motor tekin 6.5 this is for buggy.

any help would be great

thanks