The 2014–2017 Yamaha YZ450F marked the beginning of what we now know as the modern era of high-powered 450s. From this point on, these bikes only got more aggressive, more powerful and, in some ways, a bit wilder. Yamaha was already pushing the envelope with this generation, doing things very differently to everyone else and it showed.
The Yamaha YZ450F is quite an unusual bike, with the cylinder turned around so that the intake is at the front and the exhaust exits out the back. The air filter is positioned up high and in front of the tank, while the fuel load has been shifted rearward toward the centre of the bike.
Initially Yamaha used a ‘snake’ pipe, but now the header does a full lap around the barrel before meeting the silencer at the rear. The YZ is equipped with the highly regarded spring-cartridge KYB fork and a KYB monoshock at the rear. The Yamaha packs a whole lot of punch and can be tuned using the hand-held Power Tuner.
The speed-sensitive fork went into production in 2005 and has only seen minor improvements over the years. While other manufacturers experimented with air forks in an effort to save weight, Yamaha stuck with the coil-spring setup and in no great surprise, in the end, everyone else came back to it.
The KYB fork wasn’t without its early issues. One known problem was the free piston above the compression valve in the inner chamber cracking. This piston was made from plastic and had a tendency to split, which resulted in a loss of damping.
A number of aftermarket companies began producing anodised aluminium pistons to replace the OEM unit and eliminate the issue. Although the free piston looks similar in later models, the material has improved, making failures far less common.
One issue that still pops up regularly is stripped sump plugs. The solid head design gives plenty of purchase with a spanner, which often leads to people over-tightening and damaging the threads. This can be repaired with a Helicoil, but it’s something to check closely when inspecting a second-hand bike. If the plug is leaking, it’s a good indication the threads may already be compromised.
Another common problem is stripped oil filter cap bolts, so make sure to check those as well. When inspecting the bike, take it for a ride and ensure all gears engage properly and the clutch isn’t slipping. Look for any oil or coolant leaks and check all wheel and frame bearings.
On the left-hand side of the engine, there is a black plastic screen retained by a 10mm bolt. These are known to leak if they’ve been over-tightened or damaged, so it’s worth inspecting closely. Check the chain and sprockets for wear, along with the brake pads, and go over the suspension to ensure it moves smoothly without leaks.
If the rear suspension feels stiff, it’s often a sign that the linkage or swingarm bearings are worn or seized. Lastly, inspect the fuel line and the connection point at the fuel pump. If these have been handled roughly or installed incorrectly, they can leak and cause running issues.
NEW
2014 $11,999
2015 $11,999
2016 $12,099
2017 $12,099
SECOND HAND
2014 $5900 – $7000
2015 $6900 – $8150
2016 $7300 – $8650
2017 $8150 – $9700
MARKET EQUIVALENT
14–17 Honda CRF450R — $5700 – $9350
14–17 Suzuki RM-Z 450 — $6100 – $9300
14–17 Kawasaki KX450F — $5500 – $9050
14–17 KTM 450 SX-F — $6000 – $9950
FRAME
The YZ frame is made of aluminium and so is the subframe. Originally the lower engine mounts were aluminium, but Yamaha later changed them to steel.
BRAKES
The front and rear brakes are both hydraulic, with a single floating disc on the front with a twin-piston floating caliper, and a single disc on the rear with a single-piston floating caliper.
ENGINE
The 449cc DOHC, liquid-cooled engine has an impressive power curve and produces plenty of torque.
SUSPENSION
The KYB closed-chamber fork is widely regarded as one of the best handling production forks on the market while still using coil springs.
WEIGHT
The YZ450F comes in at a wet weight of approximately 112kg.
