If you’re into racing ATVs, or simply want one that will burn most other models, the Yamaha YFZ 450 should be at the top of your list.
Boasting the industry’s best power to weight ratio and built for speed, this sport ATV is especially hard to beat on the track and more than holds its own on the trail with some of the fastest ATVs available for 2024.
While its top speed and overall performance are best-in-class, there are some reasons to warn you off of this model.
This guide will detail the following:
- 5 reasons you shouldn’t buy the YFZ 450
- 5 reasons you should buy the YFZ 450
- Specs, key features & performance
- YFZ 450 top speed
- The “Big Three” modifications that make if faster
- Several other ways to maximize its top speed
- How the YFZ 450 stacks up with the Raptor 700
5 Reasons You SHOULDN’T Buy The YFZ 450
The Seat Is Uncomfortable – the seat is known to be hard, which can make riding for extended periods uncomfortable. It is also T-shaped and sloped on the EFI models to keep you pushed forward while riding, which is good for aggressive riding but can be tough on the shoulders and arms when riding trails more casually.
Build Is Uncomfortable For Bigger Riders – With a smaller build, lower handlebars and a seat that slopes down and pushes you towards the front of the ATV it can feel like you’re almost leaning over the handlebars, especially for taller riders.
Not Good For Cruising – The YFZ 450’s engine is tailor-made to go fast and is not great for idling or cruising at lower speeds. Idling and slow riding leave it prone to overheating, so if you’re more of the cruising type than an aggressive trail rider, it may not be a good fit for you.
Suspension Is Stiff – The suspension set-up makes for a firm ride, so when riding fast through rocky or rough terrain, you’ll take some pretty good jolts which can be tough on the shoulders and arms. The quad’s lighter weight also adds to the tendency for riders to get bounced around pretty good.
Fuel Capacity Limits Riding – The fuel capacity of only 2.6 gallons is minimal for a quad that excels on the trail, which limits you to shorter rides unless hauling along a can of fuel for refilling.
5 Reasons You SHOULD Buy The YFZ 450
Handling Is Amazing – At 405 lbs the YFZ 450 is incredibly easy to handle thanks to its thin frame and 50-inch wide stance, which also offer great stability in all terrains while still enabling you to ride tighter trails.
Unmatched Torque & Power – This model offers seemingly never-ending torque and power throughout the gears so you can rev the engine all the way through unlike with many other quads. The power-to-weight ratio is the best in the industry.
No Terrain It Can’t Conquer – Dunes, dirt, mud, and the toughest trails are no match for the YFZ 450’s power and well-roundedness. And with excellent speed and acceleration, it hangs with just about any model out there when trail riding.
Cornering And Power Sliding – This model corners with the best of them, offering excellent stability while doing so. And with its lighter weight, you can sling the back end around and power slide almost effortlessly without fear of flipping.
Quick Release Plastics – Unlike many other quads that are an absolute pain to remove the plastics from, this model offers quick release plastics that can be removed with a simple turn of the pin(s) holding them in place.
Specs, Key Features & Performance
Engine & Drivetrain
The YFZ 450 is powered by a 449 cc single-cylinder engine with an impressive max output of around 38 HP.
This engine provides plenty of torque and low-end power to conquer any type of terrain, along with some of the best speed and acceleration in the industry.
Pre-2009 models featured a carburetor, while 2009+ models offered EFI.
An O-Ring chain drive powers the rear wheels of the YFZ 450, which only offers 2WD.
The transmission is a five-speed manual shift, with the slipper clutch being one of the easiest clutches you’ll find when it comes to manual shifting.
| Engine Type | 4 Stroke, DOHC |
| Cylinder Arrangement | Single Cylinder, DOHC |
| Displacement | 449 cc |
| Engine Cooling | Liquid-Cooled |
| Horsepower | 38 HP |
| Fuel Delivery | EFI / Carburetor |
| Fuel Capacity | 2.6 US Gallons |
| Drive System | Chain Drive, O-Ring, 2WD |
| Transmission Type | Manual, 5-Speed w/ Multiplate Assist & Slipper |
Suspension
The YFZ 450 offers a long travel suspension, with an independent double wishbone up front and a cast aluminum swingarm in the rear.
Front and rear shocks offer dual rate spring set-up that is preload adjustable and can be tuned for a soft or firm ride.
While plenty adequate, the suspension system is known to offer a stiffer ride on even the softest preload settings and can make the ride across rough or rocky terrain rather jolting.
Wheel travel in the front (9.8 in) and rear (11 in) is excellent, as is the ground clearance of 9.3 inches.
| Wheelbase | 50 in |
| Ground Clearance | 9.3 in |
| Front Suspension | Independent Double Wishbone |
| Rear Suspension | Swing Arm |
| Travel | Front – 9.8 in, Rear – 11 in |
Tires & Brakes
Hydraulic disc brakes with dual piston calipers are found in the front and rear, with a wave-style rear rotor for better cooling.
The brakes are lever-operated and provide plenty of stopping power in rough terrain, slick surfaces, and during ascents.
The YFZ 450 is equipped with 21-inch Maxxis AT tires up front and 20-inch Maxxis AT tires in the rear.
These tires offer good traction, but if you ride tougher trails or in soft terrain often, you’ll likely want to upgrade to something a little more aggressive.
| Front Tires | 21 x 7-10 (Maxxis AT) |
| Rear Tires | 20 x 10-9 (Maxxis AT) |
| Wheels | Aluminum |
| Front Brake Type | Dual Hydraulic Disc |
| Rear Brake Type | Wave-style Hydraulic Disc |
Dimensions
The YFZ 450’s 405 lb weight offers a good middle ground between being able to take abuse while still offering easy handling thanks to its low center of gravity.
Its wider stance of 48.8 inches offers good stability while still enabling it to traverse most off-road trails.
At a height of only 41.9 inches, it sits down low to make it even more stable.
| Length | 70.7 in |
| Width | 48.8 in |
| Height | 41.9 in |
| Seat Height | 31.9 in |
| Dry Weight | 405 lbs |
YFZ 450 Top Speed
Powered by a 449cc engine with an output of around 38 horsepower, the top speed of a YFZ 450 is between 73 and 75 mph in stock condition.
This model’s acceleration is also impressive, with the YFZ 450 capable of going from 0-60 mph in around 8 seconds.
This combination lands the YFZ 450 near the top of the list of the best racing quads you can find.
While topping out at 75 mph is impressive for a machine in the 450cc class, the YFZ 450 can reach speeds upwards of 85 mph with some common modifications.
YFZ 450 Big Three
The most important factor in maximizing your ATV’s power and top speed is maximizing the airflow in and out of the engine.
The YFZ 450 “Big Three” modifications focus on upgrading the main components that affect the amount of airflow and fuel flow into your engine.
These components are the air intake system, exhaust system, and the air to fuel ratio.
Upgrading these three components are the most common modifications owners make to their YFZ 450 to increase the top speed, horsepower, and torque.
A YFZ 450 with the “Big Three” modifications should see gains in the vicinity of 10+ mph in top-end speed, 9 additional horsepower, and 9 added lbs-ft of torque.
YFZ 450 Air Intake Upgrade
The air intake system is responsible for circulating air into the engine, and ensuring that this air is free of dirt and debris that can harm the engine over time.
By upgrading your air intake system, you’ll enable more clean air into the engine so it runs at its peak performance level.
The YFZ 450’s stock intake has a tendency to limit the engine at its higher RPM ranges, so upgrading the air intake will eliminate this and give your machine more power and speed at its top RPM ranges.
With an upgraded air intake system, your YFZ 450 should add around 2-3 horsepower and 2-3 lbs-ft of torque from 5,000 RPMs and up.
While there are plenty of upgraded intake options available, the highest recommended for the YFZ 450 are:
- Fuel Customs Intake (FCI)
- Pro Design Intake
- Race Performance (RP) Intake
With an upgraded intake providing more air into the engine, there will also be a need to exit this added airflow just as efficiently as a result.
YFZ 450 Exhaust Upgrade
Upgrading the exhaust system will provide an efficient exit for the added airflow into the engine once used up.
This upgraded exhaust system is the second piece your YFZ 450 needs in order to capitalize on the added speed, horsepower, and torque from the increased circulation to and from the engine.
Aside from those benefits, an upgraded exhaust will also provide your YFZ 450 with a deeper, smoother sound while riding.
For the YFZ 450, the highest recommended aftermarket exhausts systems are the following:
- Rossier R5 Exhaust
- Race Performance (RP) Exhaust
- Empire Exhaust
- HMF Racing Exhaust
- Barker’s Exhaust
Each of these options are very similar when it comes to added performance, but all of them differ in style and the type of sound they emit.
Power Commander Upgrade
To achieve peak performance with upgraded intake and exhaust systems, you’ll want to add a power commander (or fuel controller) as well.
This tuning device will monitor the air to fuel ratio of your quad and calculate the fuel adjustment needed to provide the proper amount of fuel flow to your engine in proportion to the increased airflow.
This will result in the most efficient throttle response at every RPM level, along with increased horsepower and torque.
While you can tune your stock ECU to achieve this, common consensus among YFZ 450 owners is that replacing the ECU with a Vortex ECU will give you the best results for this model.
Additional Ways To Increase YFZ 450 Top Speed
There are a few more ways to increase the YFZ 450 top speed outside of just the “Big Three” modifications.
Delete The AIS
The YFZ 450 makes use of an Air Induction System, which is commonly referred to as “AIS”.
The AIS is an “emissions” system that pumps hot exhaust back into your air filter, which then routes it back into the engine.
This process is supposed to help prevent air pollution, but also ends up causing:
- The engine to produce less power
- The quad to run leaner
- The exhaust pipe to glow from added heat
- Frequent backfiring
Deleting the AIS system will help prevent the symptoms above and help your quad run better. It also removes unnecessary weight and cleans up the look of your engine.
To delete the AIS system, you can purchase a plate that blocks off and deletes the AIS. Many owners also install a timing plug kit to make their machines look more stylish after making this modification.
Increase The Gearing
A common way to adjust power and speed in ATVs that uses chains is to replace the front and/or rear sprockets.
To add more top-end speed, swapping out the stock rear sprocket for a slightly smaller one and the stock front sprocket for a slightly bigger one will achieve this.
The YFZ 450 is equipped with a 14-tooth front sprocket and 38-tooth rear sprocket in stock condition.
Moving to a 15-tooth front sprocket and sticking with a 38-tooth rear sprocket will add more top-end speed and longer gears, and seems to be the ideal setting for top speed and racing.
It should be noted that moving to a bigger front sprocket will result in a slight decrease in acceleration and torque.
Upgrade The Tires
The YFZ 450 comes equipped with 21-inch tires in front and 20-inch tires in the rear.
Replacing these with bigger aftermarket 22 or 23-inch tires in front and and 21 or 22-inch tires in the rear should give you a few more mph of top-end speed.
YFZ 450 vs Raptor 700
The YFZ 450 and the Raptor 700 are pretty similar in terms of top speed. In stock condition the YFZ 450 tops out at 75 mph while the Raptor 700 tops out at 77 mph.
And even after making modifications to upgrade either of these machines, they’ll both top out at around the speed of 85 mph.
But there are some key differences in performance:
- The YFZ 450 is better suited for racing and track riding than the Raptor 700.
- The Raptor 700 offers better torque and power, making it better for trail riding and dune riding.
- The Raptor is slimmer than the YFZ 450, making it better for tight trails.
- The wider stance of the YFZ 450 makes it better for cornering at any speed.
- The Raptor 700 will win a race against a YFZ 450 on straight, open roads every time assuming they’re in the same condition.
- The YFZ 450 will win a track race against a Raptor 700 every time assuming they’re in the same condition.
Conclusion
As a machine built for racing, you don’t need to look much further than the YFZ 450 if speed is at the top of your list in what you want in an ATV.
While the top speed of a YFZ 450 is around 73 and 75 mph in stock condition, making some of the modifications discussed in this guide may have you hitting 85+ mph.
To see how the YFZ 450 stacks up to some of the other faster ATVs in the industry, check out the following guides before you go:
