Since 2014, Yamaha's flagship motocross machine has only received minor tweaks to the chassis, engine, and suspension, with each year offering an improved bike that continued to climb the ladder in the highly competitive 450cc four-stroke market. But in spite of the successful 2017 machine, Yamaha has released an all-new '18 YZ450F, featuring numerous changes and some of the most innovative technology available to the consumer to date.

Yamaha has always offered (albeit sold separately) the GYTR Power Tuner, which plugged into the bike and made ignition and EFI changes possibly. For this year, though, the capabilities of the Power Tuner were taken to another level, via a phone app that is compatible with both iOS and Android phones. The app connects to the motorcycle through a secure WiFi signal, and in addition to creating and uploading custom maps, the app can also share maps with other YZ450F owners, and be set up to alert you when oil changes and other maintenance is needed.

2018 Yamaha YZ450F
The 2018 Yamaha YZ450F is completely new from the ground up, and is Yamaha’s latest generation since the YZF was given an overhaul in 2014.Jeff Allen

INNOVATIONS GALORE

Another innovation added to the YZ450F is the electric start, which adds a minimal amount of weight and removes the kickstarter. The engine is new and features several updates, including a new cylinder head and camshafts for more controllability at low- to mid-range; a new exhaust system; a new piston; and a completely new 44mm Mikuni throttle body, which helps to feed ample amounts of fuel to the new engine. Also improved is the clutch and transmission, as they are both now designed for better durability.

The chassis received equally as much attention, as the bilateral aluminum frame is completely new. The frame is designed to provide more balanced rigidity, while also moving the cylinder head further upright by two degrees for improved mass centralization and weight distribution. The rider compartment is also altered, as the steering stem position is now 6mm further forward—with a 3mm increase in trail—and the bar mounting position is now 5mm higher. Complementing the new chassis and roomier rider compartment is new, slimmer bodywork. All together, the ’18 YZF is 16mm narrower at the fuel tank and 19mm thinner at the seat and tank junction. Lastly, the YZF comes equipped with the very popular Kayaba fork and shock; both received internal improvements with the shock receiving a new larger reservoir to complement the new chassis design.

2018 Yamaha YZ450F
The engine received a new cylinder head, valves, and a new piston, as well as transmission and clutch updates.Jeff Allen

FIRST IMPRESSIONS

Sitting on the bike, our initial impression of the new bodywork and rider compartment dimensions was a lot more room to move around. After firing up the YZF with the new electric start, which is very easy whether hot or cold, we quickly became acquainted with the machine. The power comes on smooth and consistently, pulling into the top-end with authority, but without ripping your arms off. Our initial test day took place on a very loamy Glen Helen track, and because of that, we found that the loamy—more aggressive—ignition mapping made climbing GH’s hills and powering out of the deep ruts much easier. The map gave the bike a harder hit down low and allowed it to pull harder through the midrange than the standard map. It’s also worth noting that changing the map, via the new Power Tuner app, was rather easy. The new app is going to change the way we all modify our motorcycles and keep a log of maintenance in the future.

While the engine was improved and worked very well, the new chassis and suspension needed a little fine-tuning before we were completely comfortable. Last year’s bike had a very planted feel up front, but it also wasn’t the most precise turning bike of the class. For ’18, Yamaha has a new steering head position and triple clamp offset—25mm to 22mm—all of this combined gives the bike a slightly nervous feel down rough straights and when entering corners. We were able to fix this problem—for the most part—by increasing the sag from 100mm to 105mm and slowing down the high-speed compression on the shock. Those changes gave the bike a much more planted feel when entering corners.

In the turns, the more open rider compartment makes it very easy to get over the gas tank, and when compared to the ’17 model, the new bike corners much more precisely without knifing or pushing. Deep ruts are also easier to navigate with the improved chassis, as the front end remains in the rut without wanting to jump out, as had been the case with previous models. As a side note, although the new bike is a few pounds heavier than last year’s YZF, the slimmer design, and more agile turning prowess make it feel lighter while riding.

2018 Yamaha YZ450F
The airbox is redesigned and makes it much easier to remove and change the airfilter, as only one fastener needs to be removed.Jeff Allen

VERDICT?

It’s undeniable; Yamaha has successfully produced one of the most technologically advanced dirt bikes on the market to date. The app-based Power Tuner makes tweaking the bike’s power instantaneous, the innovative reversed cylinder design—now in its eighth year—works very well, and the chassis and suspension are among the best in the class. Time will tell if the new changes made to the YZ450F will stand up against its competition this year; but it’s safe to say Yamaha didn’t go backwards with the ’18 machine. It handles well, produces strong useable power, and is comfortable to ride.

2018 Yamaha YZ450F
The clutch received updates to improve durability.Jeff Allen

HITS:

  • Power is more controllable, yet still strong
  • New Power Tuner App is very easy to use and provides a lot of benefits
  • Three pre-programmed maps provide three good power choices
  • Slimmer ergonomics make it easy to move around on the bike
  • Suspension action is smooth and bottoming resistance is excellent
  • Electric start works flawlessly, easily starting the bike in gear whether the engine is hot or cold
  • New airbox is much simpler to open
  • New gas cap has a seemingly insignificant change that actually matters, making it much easier to remove

MISSES:

  • Front end feels light and slightly unpredictable at speed and over rough chop
  • Clutch tends to fade during longer motos
  • We have mixed emotions about the blue rims. They could tend to fade and look like baby blue after some time, but that has yet to be seen
  • Bars are really tall and the rider compartment feels too open from smaller/average-sized riders
  • Aggressive riders, who grip with their legs, can pop out a small portion of the right side number plate

Brendan's Gear

More photos of the 2018 Yamaha YZ450F:

2018 Yamaha YZ450F
The exhaust is updated to compliment the new engine characteristics.Jeff Allen
2018 Yamaha YZ450F
A longer exhaust header highlights the exhaust changes, while a new 44mm Mikuni throttle body feeds the engine.Jeff Allen
2018 Yamaha YZ450F
Good brakes have been a mainstay on the YZ450F and 2018 is no different.Jeff Allen
2018 Yamaha YZ450F
A huge addition to the ’18 YZF is electric start. The entire system does add weight, but it’s minimal.Jeff Allen
2018 Yamaha YZ450F
Yamaha’s launch control system returns on the ’18 YZF. It can be activated off starts and turns off automatically.Jeff Allen
2018 Yamaha YZ450F
2018 Yamaha YZ450FJeff Allen
2018 Yamaha YZ450F
Perhaps the most innovative update to the YZ450F is the app-based Power Tuner. With this app, you can make ignition changes and monitor maintenance via a secure Wifi connection with the bike. It’s also worth noting that it’s available for iOS and Android phones.Jeff Allen
2018 Yamaha YZ450F
The turning prowess of the YZF is improved over last year.Jeff Allen
2018 Yamaha YZ450F
The new suspension settings give the Kayaba fork and shock a progressive feel that resists hard bottoming off big jumps.Jeff Allen
2018 Yamaha YZ450F
Our initial day of testing took place on a loamy Glen Helen track. We found the aggressive map—which we switched to via the Power Tuner app—worked the best.Jeff Allen
2018 Yamaha YZ450F
Deep ruts aren’t a problem for the YZF. It dives in, holds a line, and doesn’t want to push out of the rut.Jeff Allen
2018 Yamaha YZ450F
Thanks to the new triple clamps and taller bar mounts, we found the rider compartment to feel slightly tall. It was easy to move around in, but we’d likely prefer to put lower bars on.Jeff Allen
2018 Yamaha YZ450F
The new bodywork gave the seat a flatter profile and slimmed the entire bike down substantially, making it easy to get over the front for cornering.Jeff Allen
2018 Yamaha YZ450F
2018 Yamaha YZ450FJeff Allen
2018 Yamaha YZ450F
2018 Yamaha YZ450FJeff Allen
2018 Yamaha YZ450F
2018 Yamaha YZ450FJeff Allen
2018 Yamaha YZ450F
2018 Yamaha YZ450FJeff Allen
2018 Yamaha YZ450F
2018 Yamaha YZ450FJeff Allen
2018 Yamaha YZ450F
2018 Yamaha YZ450FJeff Allen
2018 Yamaha YZ450F
2018 Yamaha YZ450FJeff Allen