Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/779724
2017 SUZUKI RMX450Z FULL TEST P66 in poor performance or, even worse, possible engine damage from the overly lean conditions. Basically, it's all or nothing when it comes to modifying the RMX's engine; we chose nothing, want- ing to keep it EPA friendly and green sticker-legal. We're not ready to jump into turning this into a full-blown, closed-close- only race bike just yet. With just the throttle stop removed, the RMX450Z is very rideable and delivers smooth power while doing so very quietly. Surprisingly, it puts out decent power considering how restrictive the air box and exhaust seem. It doesn't show- case aggressive or very snappy power, but it will climb some big hills when in the higher rpms. This is a detuned motocross engine geared toward off-road riding, but its heart beats best when opened up. Here, the lean fuel mixture seems to be a lesser issue and the bike runs pretty well. While the power delivery is good, and very smooth and friendly off idle, it does suffer from pop stalling, or "flaming out," often. This was also an issue we had with the 2010 model. Unfortunately, the RMX still tends to flame out at the worst possible time, every time. Every single test rider we had on the bike stalled more than once, usually resulting in a tip over or a dropped bike. The frustrating part of the flame out is that it isn't totally consistent and often happens at different rpms under different load situations. Narrow and nimble is the RMX450Z's mantra. In classic Suzuki RM-Z form, the RMX corners easily and precisely. With the added weight of elec- tric starting parts, headlight, side stand and an 18-inch rear wheel, the RMX is heavy on the scale (272 pounds we are told) but doesn't feel too bad out on the trail. A little more pep in the power department would help make the RMX feel lighter, but the small and narrow gas tank contributes to a slim motocross feel, which is a good thing for sure. When you think of a green sticker-legal bike you envision a bike ready to take on some rough and technical, maybe even slower-speed, trails. This is not exactly what the chas- sis and suspension setup of the RMX450Z is all about. Mix the flame-out tendencies with suspension that doesn't shine in rocky and rooted trails and you have a bike that really wants to be a race bike, but is stuck in green sticker-legality limits. As is, it really prefers more open spaces and higher speeds to get the suspension moving through the stroke, liking to be ridden between 20-40 mph. With momentum, front-end deflec- tion isn't as bad and the engine rpms are generally above the flame-out zone. Heavier riders (200-plus pounds) found the RMX more plush and compliant 2 0 1 7 S U Z U K I R M X 4 5 0 Z ENGINE TYPE: ........ 449cc liquid-cooled, 4-valve, DOHC 4-stroke BORE X STROKE: ............96.0 x 62.1mm COMPRESSION RATIO: .................... 11.6:1 FUEL DELIVERY: .............. EFI with 41mm Keihin throttle body LUBRICATION: .................Semi-dry sump TRANSMISSION: .... 5-speed; multi-plate wet clutch STARTING SYSTEM: ........... Electric/kick FINAL DRIVE: .........................Chain 13/51 FRONT SUSPENSION: .................... 47mm Showa coil spring, cartridge fork, fully adjustable; 12.2 inches travel REAR SUSPENSION: Showa rear shock, fully adjustable; 12.2 inches travel FRONT BRAKE: ............... Nissin, 260mm Braking pedal-style disc w/two-piston caliper REAR BRAKE: ... Nissin, 240mm Braking pedal-style disc w/single-piston caliper FRONT TIRE: . 80/100-21 Dunlop 742FA REAR TIRE: ......... 120/80-18 Dunlop 756 SEAT HEIGHT: ...............................37.4 in. WHEELBASE: ................................58.5 in. GROUND CLEARANCE: ..................12.6 in. FUEL CAPACITY: ...........................1.6 gal. CLAIMED WEIGHT: ...................... 272 lbs. MSRP: .......................................... $8999 S P E C I F I C A T I O N S