According to Kawasaki, factory Monster Energy Kawasaki team rider Jake Weimer broke his arm today while practicing for the upcoming AMA Supercross Series.The former Monster Energy/Pro Circuit/Kawasaki team rider would have made his factory debut in the 450 class at Anaheim I on January 8, but now it appears that will have to wait. Kawasaki did not give any indication as to how long the 2010 West Coast Supercross Lites Champion might be out of action.