MXA TEAM TESTED: YAMAHA GYTR YZ450F AIRFLOW KIT
WHAT IS IT? The Yamaha GYTR Air Flow kit is designed to increase airbox volume and air flow, resulting in more power on the 2018 through 2022 YZ450s and 2019 through 2022 YZ250Fs.
WHAT’S IT COST? $149.99 (Air Flow kit).
CONTACT? Your friendly local Yamaha dealer.
WHAT STANDS OUT? Here’s a list of things that stand out with the Yamaha GYTR Air Flow kit.
(1) MXA’s solution. MXA has harped on Yamaha’s airbox design for the last 12 years. In 2020 we got tired of complaining about it and built a one-off airbox that combined a Twin Air Power Flow kit with a bulbous hand-made, hump-backed airbox cover that doubled the volume of available air. It wasn’t attractive, but on the track every MXA test rider raved about the increase in throttle response and mid-and-up power. When we took it to the dyno, our jerry-rigged airbox pushed our 30-hour, box-stock YZ450F from 58.5 horsepower to an impressive 60.31 horsepower (with no mods unrelated to air). A large portion of the power increase came from Twin Air’s $259.95 Powerflow kit, which replaces the stock sealing ring with an anodized aluminum mounting plate, eliminates the restrictive backfire screen, adds a true-to-life internal filter cage and tops it off with a special, fire-resistant, domed Twin Air filter. But, the coup de grace was the large hump-backed air cover that provided a massive increase in the volume of air at the ready. We felt that our test had proven that Yamaha was leaving power on the table with its stodgy airbox design, but they didn’t act. Instead, Nihilo, CRM, Lightspeed, VHM, Slater and 3DP Moto are all offering airbox covers that increase YZ250F/YZ450F airbox volume.
(2) Yamaha reacts. After what seemed like 12 years of inaction, Yamaha, through its GYTR accessory division, introduced the $149.99 GYTR Air Flow kit for the YZ250F and YZ450F. It is not an original idea. In fact, the GYTR Air Flow kit is a less-expensive copy of the Twin Air Powerflow kit, with the major changes being a plastic sealing ring (instead of Twin Air’s CNC-machined and anodized sealing ring), a slightly larger Cycra airbox cover, a plastic airbox cage (instead of Twin Air’s machined aluminum cage) and two GYTR air filters (instead of Twin Air’s fire-resistant air filter).
We give Yamaha credit—not for creativity, but for the willingness to do something about the limitations of its existing airbox design and to do it in a way that makes it affordable for a larger YZ-F audience. Additionally, GYTR has a well-earned reputation for having Yamaha’s test department run every GYTR product through a rigorous test regimen before it is offered for sale. The GYTR Air Flow kit produces a noticeable increase in throttle response.
(3) Installation. It could be easier, but if you follow the instructions all it takes is a Phillips-head screwdriver and 30 minutes to swap the stock Yamaha sealing ring for the GYTR unit.
WHAT’S THE SQUAWK? Four quibbles. (1) As if the YZ250F and YZ450F weren’t loud enough already, the increased airflow and volume of the GYTR Air Flow kit create added noise. (2) We wish GYTR had gone much larger on the volume inside the airbox cover when they had the opportunity to do more than retro-fit the five-year-old Cycra cover, which is larger, but not as large as possible. (3) Without the backfire screen, there is the constant danger of dirt falling down into the downdraft intake (if it does, use a shop vac to suck it out immediately). (4) It leaked dirt at the back of the filter cage—and not just a little dirt. It had some interference with a base plate bolt and we had to grease the filter to eliminate leaks.
MXA RATING: Proven Twin Air innovation at a bargain price, but needs extra care.