Honda NX250 Dominator 1988-1990 Service Manual

ADV Rider's own retrospective doesn't mince words: "the world wasn't ready for a 250 adventure bike" back in the late 1980s, and it's exactly why the NX250 remains, decades later, "truly ahead of its time" with a formula "no current motorcycle has quite nailed," despite the CRF250 Rally coming close in some respects. Sold in the US for just three model years before being discontinued in 1990 (production continued longer in European and other international markets), it's a genuinely rare survivor today — one AdventureRider owner test called finding a well-kept example "hard, because there are so few of them."

Power comes from the all-new MD21E 249cc liquid-cooled single, DOHC with 4 valves and an 11.0:1 compression ratio, delivering a claimed 26 hp at 8,500 rpm and around 17 lb-ft of torque at 7,000 rpm, run through a genuinely long-legged 6-speed transmission with chain final drive and electric start. What made this engine remarkable for its era: liquid cooling when most rivals — even larger-displacement dual-sports — still ran air-cooled setups, plus extraordinarily long service intervals, with valve adjustments needed only every 24,000 miles after the initial break-in. Real-world owner reports back up the impressive efficiency, with one longtime rider recording over 85 mpg while still comfortably holding 70+ mph highway speeds.

The tubular steel double-cradle frame carries a 37mm telescopic fork with 8.7 inches of front travel and a Pro-Link rear shock offering 7.9 inches, delivering genuine dual-sport composure over rough terrain. A single front disc paired with a rear drum brake handled stopping duty — adequate, if unremarkable even by period standards. Styling included a small front cowl with integrated headlight, a one-piece dual seat, an under-seat exhaust routing, and wire-spoke wheels (19-inch front, 16-inch rear). Honda also built a Japan-market variant, the AX-1, sharing the same core platform with a front disc brake in place of the standard NX250's drum. Dry weight comes in at a genuinely light 260 lbs, with a 32-inch seat height and a modest 2.4-gallon fuel tank.