Last season we added a beater spee up kit from Deere with part numbers H135850 and H135840 to our 9500. Is this the correct kit? We are happy with the performance, just want to make sure we are not running the beater to fast.
The kit you should use is BH78623, which is a whole goods # that includes the 2 pulleys and a belt set. The numbers you gave are probably for the pulleys if you buy them separately. You will pay double for the kit if you buy it in individual part numbers.
You are running the beater 33% faster with this kit. You are not running it too fast, in fact if you go to the PF 60% speed up kit your beater speed will exactly match your cylinder speed.