Hot Rods – Counter Balancer Kits, including kits for the Honda TRX 450R 450cc, TRX 500 FE/FM, TRX 350 FE/FM/TE, Polaris Scrambler 1000 XP, Hawkeye 400 HO and Yamaha Grizzly 350 and 450 IRS 4x4. The balancer system is what keeps a big single from shaking itself apart, and on an ATV that spends its life at part throttle in ruts, mud and trail chatter, a worn balancer gear, chain, tensioner or bearing is a common cause of new noise and vibration after high hours. These kits bundle the balancer shaft components, gears and bearings you need during a bottom end refresh so the counterweight stays timed to the crank instead of hammering the case. Correct balance means less stress on crank bearings, cases and motor mounts, fewer cracked plastics and loose fasteners, and a quad that stays comfortable through a long day of riding or hauling. It also protects the machine work you just paid for. Sorting ATV counter balancer parts by year, engine and model code matters, since Honda and Polaris changed shafts mid-run, so send us your year, model and displacement and we will confirm the correct kit fits your machine before you order.