The bore × stroke dimensions of the engine in the RM80 were changed from 49 × 44 mm in the previous model to 48 × 44 mm, increasing maximum horsepower from 17 to 19 PS. Maximum horsepower was further increased to 22.5 PS in the 1983 model by the adoption of a liquid cooling system.

This RM80 is equipped with a liquid-cooled 2-stroke 80 cm³ engine with a power reed valve and squared-off bore × stroke dimensions (the 48 × 44 mm dimensions of the previous model were adjusted to 46.5 × 46.8 mm). Maximum horsepower was increased from 22.5 to 23.5 PS. New front disc brakes help to realize superb braking force and maneuverability. The adoption of a newly designed frame consisting of elliptical pipes made of high-tension steel increases the rigidity of the frame while creating smoother leg and foot contact.

Following the smaller-wheeled model that debuted the previous year with a 17-inch front tire and 14-inch rear tire, the RM80L features a larger 19-inch tire at the front and a 16-inch tire at the rear, as well as an extended swingarm and front forks to match the larger wheels. These changes helped to realize dramatic improvements in road handling, stability, and traction without affecting the overall balance of the base model, enabling riding performance a cut above bikes in the same class.

To comply with changes to the regulations issued by the International Motorcycling Federation (FIM), the bore × stroke dimensions were increased from 46.5 × 46.8 mm in the RM80/L to 48 × 46.8 mm, raising the displacement of the engine to 85 cm³. The RM85/RM85L also feature Suzuki’s first inverted front forks in this class.