Transmission Gears (4 Speed Manual Shift) 125cc 54mm ATVs & Dirtbikes

Four-speed manual transmissions on 125cc 54mm ATVs and dirt bikes rely on precisely machined gears to deliver smooth acceleration and reliable power transfer. When these gears wear, chip, or lose alignment, shifting can become rough or inconsistent. This collection includes replacement gear sets designed to restore dependable performance on Honda-type 125cc 54mm manual-shift engines.