From rotary valves to reed valves to power valves, over the decades, engineers have tried multiple pathways to improve the output and broaden the powerband of two-stroke engines. Like most modern two-strokes, the KX85 mini-motocrosser has reed-valve induction, but it also offers an exhaust power valve, which not all similarly sized machines can boast. Controlled by engine rpm and throttle position, the power valve adjusts exhaust-port timing to conditions, giving the KX85 a meatier powerband and thus a competitive advantage.
There is more to love besides the KX85’s powerband though, including an inverted fork, 10.8 inches of multi-adjustable suspension travel at both ends, and a low wet weight of 165 pounds. Don’t let the steel frame scare you away. While not as “modern” a material as aluminum, on the KX85, the tidy dimensions of the steel tubes contribute to a slender machine that’s more suitable for smaller riders. No big-wheel version is offered, so when growing riders turn into beanpoles, they’ll have to hit the aftermarket for parts or else step up to a KX100 or a competitor’s 125 as the next step.
Likes: Seriously fast, adjustable handlebar mounts, great appearance
Dislikes: Lags behind big bikes in suspension tech
Verdict: A serious racer that is also forgiving for novices