I am haveing trouble with mr 07 wr 450, elec start

I am haveing trouble with my 2007 wr 450, elec start wont work and when im rideing my speedo isnt working properly as it comes up with random numbers like im doing 200kph when im doing more like 50, it also makes a buzzing noise from some sort of relay when i go to use electric start, im not sure what it is but its located under the seat beside the battery