When I got my XP 900 I found the throttle spring much harder than my older 800. Luckily it was an easy swap over (5min) and I just exchanged one for the other. But yes as indicated above the Ace throttle spring is reversed from the RZR's. So anyway we just removed the spring and a local chap remade a spring with less tension. In fact he used my RZR spring as a guide to match the tension. Pretty simple and Cheap solution.