The Yamaha YFZ450R has been a very popular sport ATV and is currently the only 450cc sport model in production. Released in 2009, the Yamaha YFZ450R has received a few minor changes. The most notable changes happened in 2014, when Yamaha changed to the Assist and Slipper clutch, increased compression, and revised the cam profiles. Yamaha also revised the exhaust and connecting rod, updated the ECU mapping, and added emissions equipment. These are very reliable sport ATVs, but there are a few upgrades that it can benefit from. Here is a list of the top five upgrades for the Yamaha YFZ450R.
As someone who owns a few YFZ450Rs and has built many to be competitive ATVMX race machines, I am very familiar with the platform. From riding and maintaining them in various forms, from stock to pro-level race-ready, I have seen various upgrades that will really help the YFZR get to the next level. These upgrades are for any skill level and will benefit riders who find themselves in the woods or on the motocross track.
#1. Yamaha YFZ450R Sprocket Guard/Chain Guide
The first of our Yamaha YFZ450R upgrades is a sprocket guard, or if this is a motocross-focused machine, a chain guide. These will both help protect against chain derailment. A derailed chain can lead to damage and also be a major headache. I have seen engine cases get damaged, as well as the swingarm, from the chain coming off the rear sprocket. From the factory, the stock skid plate has a small plastic chain guide built in that wears quickly.
A sprocket guard will mount alongside the rear sprocket and protect the whole circumference of the sprocket. This is going to be the option for trail riders and woods racers, and it can also be used for beginner-level motocross. A sprocket guard also helps reduce the chances of bending a sprocket from impacts. The Teixeira Tech Sprocket Guard is a great option for keeping the sprocket safe.
Another guide option will be for motocross-prepped machines. This includes a chain guide and mount. The bracket will allow for a protective chain guide to bolt on. The chain will then pass through the guide to the rear sprocket, greatly reducing the chance of chain derailment. The Walsh Racecraft Chain Guide Mounting Bracket and Chain Guide pair together to do the job. This will replace the factory rear skid plate and will also require one hole to be drilled and tapped for mounting.
https://teixeiratech.com/YFZ450R-Sprocket-Guard_p_57.html?AffId=2
https://walshrc.com/product/yfz450r-chain-guide-mounting-bracket/
https://walshrc.com/product/rear-swingarm-chain-guide/
#2 Yamaha YFZ450R Case Saver
A good aftermarket case saver is necessary for any sport ATV, including the Yamaha YFZ450R. Just as in the previous upgrade, a case saver will add protection in case of a chain-related issue. If a chain derails, fails, or brings debris along, a case saver does exactly what the name describes: protect the engine cases from damage. As someone who has had a chain fail, break a factory case saver, and crack the left engine case, I am a strong believer in a good aftermarket case saver.
The Moose Racing Poly Case Saver is a great option. With polyurethane construction, it’s molded to conform completely to the engine for maximum protection, while also reducing stress on the case saver mounts.
https://motosport.sjv.io/VODP3k
#3 Yamaha YFZ450R Chassis Skid Plate
Yamaha equips the YFZ450R from the factory with a small plastic skid plate that mounts under the engine. Replacing the stock skid plate with a larger, stronger skid plate is a must for most forms of riding. An aftermarket skid plate will protect the bottom of the whole frame, from the bumper mounts to right in front of the suspension linkage mounts. This gives you more protection for both the engine and the bottom frame rail from foreign objects like logs or rocks. For trail and cross-country riders, this is one of the most practical Yamaha YFZ450R upgrades.
There are two different materials that aftermarket skid plates are made from: aluminum or plastic. Aluminum is preferred for cross-country racing for its resistance to breaking or gouging. Plastic is preferred for motocross for its ability to glide over obstacles more easily.
For aluminum skid plates, Ricochet makes a great option with their 3/16-inch-thick 5052 H-32 aluminum construction. Ricochet also makes aluminum swingarm and A-arm skid plates to maximize protection.
For plastic skid plates, TM Designworks makes a great product with a 6-millimeter-thick skid plate with silicone additives for better friction reduction.
Both options come with mounting hardware as they utilize more mounting locations than the factory skid plate.
https://www.rockymountainatvmc.com/parts/ricochet-full-chassis-skid-plate-p?ref=1102
https://www.rockymountainatvmc.com/parts/ricochet-bullet-swing-arm-guard-p?ref=1102
https://ricochetoffroad.com/products/yamaha-yfz450r-a-arm-guard-set
https://www.tmdesignworks.com/p-1202-atv-standard-6mm-frame-plate-brpn-yafp-r450.aspx
#4 Yamaha YFZ450R Breather Box
The Yamaha YFZ450R comes stock with a crankcase breather that runs back into the airbox. The way the YFZR’s engine and valve cover are designed, oil will pass through the crankcase breather during aggressive riding. When this happens, the factory breather system has an inlet port higher than the breather port, which can pump oil into the airbox and all over the air filter.
Installing an aftermarket breather box relocates the air-oil separator, putting the vent higher than the inlet and allowing the oil and air to properly separate. The oil can then flow back into the engine while the air exits through the vent line.
DBR Race Products makes a breather box that is moved onto the left side of the cylinder. This allows for nice, short lines to be run while simplifying the entire system and allowing it to work properly.
https://www.dbratv.com/product-page/yfz-450r-breather-boxyamahaatv
#5 Yamaha YFZ450R Big 3
When you’ve installed all the parts to make your Yamaha YFZ450R stronger and longer-lasting, it may be time to add some power. The best and biggest power gains for the YFZR come in the form of the “Big 3.” The Big 3 refers to an aftermarket intake system, full exhaust system, and an ECU or fuel controller. These machines really wake up with the added flow of an aftermarket intake and exhaust. With the exhaust and intake upgraded, a fuel controller is needed to make the machine run properly. For riders looking for more power, the Big 3 is one of the most effective Yamaha YFZ450R upgrades.
A Vortex ECU is the best option for a fuel controller on the YFZ450R. As a standalone ECU, the Vortex makes the machine run better even in completely stock trim and is fully programmable. As you do more upgrades, you can change your mapping to adjust fuel trim and ignition timing as needed. If you get your Vortex set up correctly, you can have up to 10 maps to switch between.
The Rossier R5 is a great full exhaust system that will give you significant power gains. A carbon fiber end cap will also ensure a great look. The R5 exhaust is available in both stainless steel or titanium construction. The titanium option is for those looking for a lighter weight option.
Fuel Customs produces an intake system that really opens the YFZ450R’s ability to breathe. The Fuel Customs intake comes with a new intake tube, mounting bracket, and if you select it, an airbox. The “airbox” model is more of a shroud that covers the bottom and sides of the air filter, suited great for riding in dry conditions. If you are riding a lot in wet conditions, where mud becomes an issue, I recommend purchasing Fuel Customs’ XC/GNCC airbox and battery box combo.
If you are installing the Fuel Customs intake on a 2014-2027 YFZ450R, make sure you select to purchase an AIS Block-Off Plate as well. When installing an aftermarket intake on the YFZ450R, you will no longer have the Air Induction System (AIS) port to plumb into. Therefore, the system will no longer operate like it should, and should be deleted.
https://www.rossiereng.com/product/vortex-x10-ecu/
https://www.rossiereng.com/product/r5-stainless-exhaust-yfz450r/
https://www.rossiereng.com/product/r5-titanium-exhaust-yfz450r/
https://shop.fuelcustoms.com/product-p/in009-15-bx.htm
Honorable Mention: Steering Stabilizer
Not all Yamaha YFZ450R upgrades are focused on power or protection. The Yamaha YFZ450R is a great handling ATV. Fatigue from bump feedback through the steering is a common issue on sport ATVs due to their lack of power steering. The Precision Race Products Pro4 steering stabilizer is another great upgrade for any ATV without power steering. The Pro4 stabilizer has 2 adjustments, 1 for straight and 1 for turning. Adjusting these will affect how well it absorbs the shock and jarring if hitting an obstacle. If this was a Top 6 upgrade list, the Precision Pro4 would be in there for sure!
https://precision-rp.com/YFZ450R-SE_c_2324.html?AffId=23
Conclusion
Once you’ve made these Yamaha YFZ450R upgrades for durability and power, you can take the machine in many different directions. Whether you’re riding for fun or getting into motocross, cross-country, or flat track, the upgrade options are endless. This list is just a starting point. There are plenty of performance, suspension, armor, and comfort upgrades, and it all comes down to rider preference.
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