Yamaha YFZ450 & YZ450F: Unpacking the Power

The Yamaha 450cc machines, be it the YFZ450 quad or the YZ450F motocross bike, are iconic for their raw power and competitive edge. A common query among enthusiasts often revolves around the YFZ450's actual engine size, and whether it truly lives up to its '450cc' designation. This article aims to shed light on this, and then delve into the intricate world of performance tuning for these formidable machines, particularly focusing on the 2020 Yamaha YZ450F's highly sought-after setup recommendations.

The Yamaha YFZ450 is, indeed, a 450cc class machine, known for its potent four-stroke engine. However, the true magic often happens when specialist tuners get their hands on it, unlocking hidden potential. CT Racing, for instance, has long been a pioneer in extracting incredible horsepower from the YFZ450 motor, demonstrating what's truly possible beyond the factory specifications. Their extensive research and development have shown that while many focus purely on peak numbers, a well-rounded power delivery, particularly in the bottom and mid-range, can be far more effective on the track.

CT Racing's 'Sonic pipe', contrary to popular belief, isn't just about top-end power. Their philosophy centres on enhancing the crucial bottom and mid-range, which is where most riders spend their time and need immediate, responsive power. Yet, through their rigorous R&D process, they've consistently achieved more peak horsepower than many competitor pipes, solidifying their position as producers of some of the highest horsepower-producing exhausts on the market. This claim isn't just marketing hype; it's been consistently proven in multiple Dirt Wheels Magazine pipe shootouts, a testament to their engineering prowess.

For those looking to significantly upgrade their YFZ450, CT Racing offers a 'plug and play' kit that includes precise jetting and valuable tips for air temperature and altitude correction, ensuring optimal performance across various conditions. To truly maximise the gains, they highly recommend integrating the Pro Design Pro Flow filter system, which complements their modifications perfectly by allowing the engine to breathe more efficiently.

Unleashing the YFZ450 National Motor Package

For serious racers and performance enthusiasts, CT Racing's National Motor Kit for the YFZ450 and YFZ450R motor is a game-changer. Priced at £2,195.00, this comprehensive package transforms the stock engine into a dominating force on the MX racing scene. It's designed to develop approximately 58 rear wheel horsepower, offering a remarkably wide power curve that's incredibly fun to ride.

The kit is extensive and meticulous, ensuring every component works in harmony to deliver maximum output. Here’s a breakdown of what the National Motor Package includes:

• CT Racing National Port Job: Optimises the cylinder head's intake and exhaust ports for improved flow.
• CT 5 Angle Radius Valve Job for Oversize Valves: Enhances airflow around the valves, crucial for higher performance.
• 5 Del West +1mm Titanium Valves: Lighter and stronger valves that allow for higher RPMs and better flow.
• CV 4 Valve Springs and Valve Spring Base Washers: Ensures the valves open and close precisely at high engine speeds without float.
• Web Camshafts Performance Camshaft: Custom-ground camshaft to alter valve timing and lift for increased power.
• CT Diamond Hone Cylinder and Fit Ring End Gap: Precision honing for optimal piston ring seal and reduced friction.
• JE High Compression Piston: Increases the engine's compression ratio for more explosive power.
• Complete Top End Gasket Set with Valve Stem Seals: All necessary gaskets and seals for a complete and reliable rebuild.
• CT Racing Cleans and Preps Your Head, Assemble and Shims the Cams for You: Professional assembly ensures correct valve clearances and optimal performance.

To benefit from this package, owners need to ship their complete top end cylinder and head, along with a good set of stock cams, to CT Racing. It's crucial to note that to achieve the absolute maximum horsepower from this setup, a good competitive exhaust system is essential, as the kit is designed to work in conjunction with an optimised exhaust flow. For those seeking even more power, particularly for Open Class racing, there's also the option to add a Big Bore Kit, further increasing the engine's displacement and output.

Mastering the 2020 Yamaha YZ450F: Suspension & Performance Tuning

Moving from the quad to the motocross track, the 2020 Yamaha YZ450F has earned widespread acclaim, consistently winning shootouts thanks to its completely redesigned frame and engine layout. It's a machine that truly inspires confidence and encourages faster riding, making it a favourite among racers and enthusiasts alike. While the stock setup is impressive, fine-tuning can unlock its full potential, particularly for riders looking to gain an edge.

The 2020 YZ450F features a stiffer suspension package from the factory, giving it a more 'race-ready' feel. However, even this can be refined. Initially, once the suspension is broken in, it can feel slightly soft on larger bumps at speed. Adjusting the action to be slower and stiffening the compression can dramatically improve the bike's stability and planted feel around the track. The KYB suspension on the YZ450F is renowned for its comfort, yet it also provides exceptional track toughness, simplifying setup and reducing rider fatigue.

The following settings are highly recommended for most riders weighing between 170-200 pounds (approx. 77-90 kg), offering a superb balance for a wide range of tracks and riding styles:

Engine & Power Tuner App: Dialling in Your Power Delivery

The 2020 YZ450F’s engine, coupled with the Yamaha Power Tuner App, offers unparalleled customisation of its power delivery. While many maps exist, two stand out for their effectiveness across different riding conditions.

The stock engine can have quite an aggressive 'bark' from 0-10% throttle opening, which can be too much for certain track conditions, particularly on harder-packed or slicker surfaces. For riders on the East Coast of the US, with their typically softer soil, the 'Keefer 1' map is often ideal. It provides ample bottom to mid-range power delivery to get out of soft sections, yet remains manageable and linear enough to hold onto comfortably through a long moto.

For most other riders, especially those on the West Coast or on tracks with varied conditions, the 'TP 3.0' map is highly recommended. This map offers a linear and easy-to-roll-on throttle delivery, combined with a longer pulling power that makes the bike feel like a 'tractor' around the track – incredibly effective for maintaining momentum and drive. This map has been proven to deliver excellent holeshots and a significantly improved connection to the rear wheel for the 2020 model. It's also worth noting that both the 'Keefer 1' and 'TP 3.0' maps are fully compatible with the 2019 YZ450F, offering a great upgrade for previous year models.

Muffler System: Stock vs. Aftermarket Considerations

While many riders immediately look to aftermarket exhaust systems for performance gains, the stock muffler system on the 2020 YZ450F is remarkably good. It's a well-engineered component that doesn't necessarily need immediate replacement. While aftermarket options like Akrapovic, Pro Circuit, and FMF are often tested, the stock Yamaha muffler delivers commendable performance and durability. Riders should not feel pressured to upgrade immediately; the stock system is perfectly capable of competitive performance.

Handlebar Set Up: Ergonomics for Enhanced Control

Ergonomics play a crucial role in rider comfort and control. For some, the stock 2020 Yamaha YZ450F handlebar setup might feel a bit off, particularly in how it positions the upper body through corners and into ruts, potentially affecting cornering speed. A common solution is to revert to the 2019 stock hole placement, which involves using the rear hole with the mounts forward. This setup can significantly improve the rider's comfort and confidence in corners.

Regarding the handlebars themselves, the stock Yamaha bar bend is often preferred due to its comfortable sweep. However, for riders seeking a little more flex, a Pro Taper EVO SX RACE bar (which shares a similar bend to the stock Yamaha bar) is an excellent alternative. The key difference lies in the wall thickness: the stock Yamaha bar has a 5mm wall, while the Pro Taper EVO has a 4mm wall, providing that desired increase in flex for improved rider comfort and reduced arm pump.

Seat: Improving Rider Position and Transition

One area often highlighted for potential improvement on the Yamaha YZ450F is the seat. The stock seat can break down relatively quickly, leading to a feeling of 'riding in' the bike rather than 'on top' of it. This can hinder the crucial sitting-to-standing transition out of corners, a manoeuvre that's vital for maintaining momentum and soaking up impacts with the legs, which is always faster than seat bouncing.

Yamaha's own Accessory (GYTR) 20mm taller seat is a highly effective upgrade. It positions the rider more 'on top' of the bike, significantly improving the transition from sitting to standing and allowing for better body positioning. If the GYTR seat isn't an option, aftermarket solutions from companies like gutsracing.com offer firmer or taller foam options that can address this issue, providing a more supportive and performance-oriented platform.

MX3S Front Tyre: Cornering Confidence

While the stock Dunlop MX33 front tyre is competent, many riders find that the Dunlop MX3S front tyre offers a superior feel for initial lean into corners. This subtle change can make a significant difference in cornering confidence and precision, allowing riders to commit more aggressively to turns. Despite being a highly sought-after tyre, the MX3S has seen availability fluctuations, but it is making a return to stock, making it a worthwhile consideration for those looking to enhance their YZ450F's cornering prowess.

Gearing: Optimising Torque and Drive

The gearing on the 2020 Yamaha YZ450F is surprisingly versatile straight from the factory. The stock 13/49 setup is perfectly adequate for approximately 90% of tracks, largely due to the Yamaha engine's impressive torque output. This engine is so 'lugable' that it can comfortably pull third gear through most corners, even for novice riders, significantly reducing the need for excessive gear changes and preventing stalling. While a 13/50 setup might seem appealing for novice riders seeking more bottom-end, the stock gearing generally proves more effective due to the engine's inherent power delivery. Riders should simply remember to cover the clutch lever for fine control through corners.

Triple Clamps/Offset: The Virtue of Stock Components

In the quest for performance, many riders often consider aftermarket triple clamps or changes in offset. However, for the Yamaha YZ450F, this is generally an unnecessary expense and can often be a step backward. The stock triple clamp on the YZ450F possesses an exceptional rigidity balance, blending comfort with performance in a way that is difficult for aftermarket clamps to replicate. Investing in unnecessary parts can upset this delicate balance.

If you're still struggling with cornering, instead of purchasing new clamps, consider making minor adjustments to your existing setup. Two highly effective solutions are to reduce the shock sag to 102mm or to increase the fork height to 7mm. It's crucial to try one adjustment at a time, not both simultaneously, to maintain the bike's overall balance and preserve the superb bump absorption characteristics of the chassis and stock clamps. The Yamaha YZ450F offers the most comfort and performance with its stock clamps, so resist the urge to buy parts you don't truly need, as it can hinder your optimisation efforts.

Cycra Powerflow Shrouds: A Visual and Feel Enhancement

For those who prefer a thinner mid-section feel and visual appeal, Cycra Powerflow shrouds offer a compelling upgrade. These shrouds are designed to be thinner at the top compared to the stock pieces, providing a more streamlined aesthetic and a slightly narrower feel when squeezing the Yamaha while standing. This can enhance rider comfort and control, particularly during aggressive riding.

Frequently Asked Questions (FAQs)

Q: Is the YFZ450 a true 450cc?
A: Yes, the Yamaha YFZ450 is indeed a 450cc class ATV, referring to its engine displacement and category.

Q: What's the main benefit of CT Racing's YFZ450 kit?
A: CT Racing's kit significantly increases the YFZ450's horsepower, especially in the crucial bottom and mid-range, leading to around 58 rear wheel horsepower, making it highly competitive for MX racing.

Q: Are the 2020 YZ450F suspension settings suitable for all riders?
A: The provided 2020 YZ450F suspension settings are a great starting point for riders weighing between 170-200 pounds (approx. 77-90 kg), but individual adjustments may be needed based on rider preference, skill, and track conditions.

Q: Do I need aftermarket triple clamps for my 2020 YZ450F?
A: Generally no. The 2020 Yamaha YZ450F's stock triple clamps offer an excellent balance of comfort and performance. Aftermarket clamps are often unnecessary and can sometimes negatively affect the bike's handling characteristics.

Q: Can the engine maps for the 2020 YZ450F be used on a 2019 model?
A: Yes, the recommended 'Keefer 1' and 'TP 3.0' engine maps are fully compatible and can be used to optimise the performance of 2019 Yamaha YZ450F models as well.

Conclusion

Whether you're tearing up the trails on a YFZ450 or dominating the motocross track on a YZ450F, Yamaha's 450cc machines are built for performance. While the YFZ450 is unequivocally a 450cc machine, its true potential can be unlocked through expert tuning and comprehensive engine packages, transforming it into a formidable racing quad. Similarly, the 2020 YZ450F, with its advanced chassis and engine, offers incredible performance straight out of the crate, but can be meticulously fine-tuned through precise suspension adjustments, engine mapping, and ergonomic refinements. By understanding and applying these insights, riders can truly unleash the full capabilities of their Yamaha 450cc machine, ensuring an exhilarating and competitive riding experience.

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