Photos by Trevor Hunter/Jimmy Lewis
Suzuki is back with the RMX450Z for 2017. This bike was first released in 2010 but quickly dropped from the line after it was discovered there were some expensive issues looming from the Environmental Protection Agency (EPA). Now it is back with one significant change, an ECU that can not be altered. The RMX is a fully legal and compliant “green sticker” bike. Dirt Bike Test picked up our test machine and got to riding.
To be thorough, we rode the bike absolutely box stock. In this form the RMX is limited to somewhere about 20 horsepower with the use of throttle limitation. Here the bike runs like a good playbike but it is not the real reason anyone is buying a 450cc machine in the first place. Unless you want the best suspension and chassis but can’t find it with very docile and easy to ride power.
Very quickly we removed the throttle limiting device (a T-25 bolt on the throttle body) and then felt the real power (or most of it). Here, with the additional 67.9% of the throttle available, the bike starts to run a lot more like a 450. It is still very quiet and we’d put the power in the near 40 horsepower range. We then removed the intake baffle/snorkel where the bike gained throttle response and revved quicker. At this point we’d call the bike plenty powerful and rideable for any trail riding while still being whisper quiet.
We then removed the exhaust baffle and the bike jumps in performance especially in torque and pick-up at lower RPMs but it also jumps in sound quite a bit. And it does sound lean, especially on deceleration, to the point we feel we will need to do some adjusting of the fuel mixture to ride it in this closed-course competition setting. It is not as rideable in the low to mid-range based on tractability as the bike surges a little–but if you are on the gas hard with RPM and big throttle openings you won’t be bothered. We’d leave the baffle in the muffler and have it for trail riding and have a dedicated racing muffler for when that performance was needed. We are getting an FMF Powercore 4 and a JD Jetting Tuner to test in the near future. There is potential in this motor for racing applications like we know from the RMZ450.
The motor has a chunky power feel and compared to a lot of the quick-revving 450s of today a refreshing throwback to fans of earlier four strokes. Thumpers if you will. The clutch pull is average and the shifting is solid. The gear spread is wide-ratio. Not too much but it is noticeable when you ride with a MX close ratio bike. First is a little lower and fifth pulls longer with a little more gap between gears.
The bike is very thin and acts pretty light for an off-road bike. Additionally, the RMX has a very stable and stiff feel too. It acts planted with a steering feeling that is light but reluctant to shake or deflect. The bike hits the scales at 270-pounds full of its 1.6-gallon of fuel. It feels this heavy at times but in a good way helping the bike get traction–the RMX never feels porky.
On the suspension side it seems Suzuki has gone for a stiffer setting than what most trail bikes have. But it is still not motocross stiff. We will play with the suspension a lot more in the near future to see where it really fits in. But on our short ride it was acceptable and we did not play with clickers at all.
Where does this put the RMX450Z? Well after the bike was sitting on mothballs and not appearing in the US for over five years, an interesting thing might have happened. Bikes got stiffer in chassis and in suspension settings (something that the original RMX450 was) and maybe Suzuki was ahead of the game or just plain too early. Right away we loved how the bike turned for being so stable, the torquey four-stroke power for being nice and quiet and how thin it was. If you are a Suzuki fan looking for more than a DR-Z can offer yet knowing that a pure MX bike will not fit the bill, you are now covered by Yellow. We’re riding it on more places and in different configurations and we’ll get you the full test after we know the bike inside and out.
6 Responses to “2017 Suzuki RMX450Z–First Riding Impression”
Jimmy Lewis
We updated our comment about the clutch pull being light. We must have felt strong on the first ride. When compared to other bikes it is more of an average effort pull.
Mike
Thanks Jimmy for the review. I’d thought about buying one of these in 2010, but missed out. The RMX sounds like a great bike for a more aggressive rider in more open terrain. I’ve heard it’s tough to keep running just off idle in low-speed sections, with the clutch tough to use. Is this true with the 17? If true, is there some help for that?
Jimmy Lewis
There are some issues when uncorking the bike and we are working through those now. Before we bitch about we’ll work on a solution. Waiting for a JD Jetting Tuner to add some fuel in the lean spots. Especially when the muffler in opened up or when temperature is very low.
The 17 is the same bike with a different ECU.
DozensOfUs
Great write up. I’m drooling over this bike man.
Jimmy Lewis
The ECU had a second map from the factory and somehow that violated laws for compliant vehicles.
For competition use the JD Tuner interrupts the signal at the injector and does not have any effect on the ECU. It plays with the injector timing after the ECU.
A KTM XC-W was corked up to meet the standards it needed to. Now KTM only sells an EXC because the standards are not that much different between on-road and off-road for sound and emissions compliant vehicles. A lot of the way a bike is delivered is how the manufacturer decides to comply with the regulation.
I personally feel the regulations are a joke and do not help solve the problem they are trying to fix. They just create more obnoxiously loud bikes or force riders to use other methods to get what they need. Typical, your government trying to solve problems with bureaucracy and forms instead of common scene.
Rich
Fair enough, I look forward to reading about what you guys are able to tuning wise. Also, is it possible or even worth the effort to install a RMZ ECU? If the connector is different a quick trip over to Allied Electronics can fix that. Then it’s just a wire color and correct pinout deal.