MXA TEAM TESTED: TWIN AIR 2025–2026 KX250 POWERFLOW KIT

WHAT IS IT? This PowerFlow kit from Twin Air was designed for the 2025–’26 Kawasaki KX250. Kawasaki’s airbox problems started in 2024 when their new KX450 came with a flat-piece-of-toast air filter, which had very little surface area and a less than stellar seal. In 2025, Kawasaki switched out the toast for a domed filter for the 2025 KX450 and KX250 models. The slide-in-style filter is easy to install, but it’s also easy to push dirt into the intake, and it’s easy for the filter to come loose. The stock design also limits air volume and flow into the intake, which makes the bike quieter and slower. The Twin Air PowerFlow kit promotes airflow, has more filter surface volume and offers a more secure filter seal. 

WHAT’S IT COST? $359.95.

CONTACT? www.twinair.com, www.dominuscorp.com or your local dealer. 

WHAT STANDS OUT? Here’s a list of things that stand out with the Twin Air PowerFlow kit for the 2025-2026 Kawasaki KX250.

(1) Sound requirements. Kawasaki came out with their brand-new KX450 in 2024, and the KX250 followed suit in 2025, gaining an updated engine, new 450 frame and Showa suspension (instead of Kayaba, which previously came on the 250 model). Unfortunately for Kawasaki, they obeyed the FIM’s and AMA’s requests to make their bikes quieter by meeting the new 109-decibel sound target. Sadly, the 109-decibel level has been a moving target, and Kawasaki sabotaged their bikes a few years too early. The 109-deicbel requirement was supposed to meet the sound standard for the 2025 Supercross season, but it got pushed back to 2026, and now it’s been pushed back to 2027. It’s a lot harder for OEMs like Kawasaki to make changes on a whim; they have to test and develop bikes years in advance, and they can’t comply with race organization rules if they keep changing them.  

(2) Concept. Twin Air works closely with many factory teams, including the factory Kawasaki teams in Europe and the USA who helped them develop this kit. Originally, Twin Air hoped their KX450 kit would work on the 250, but the intake is slightly different for the KX250, requiring its own unique system. The Twin Air PowerFlow KX250 kit comes with a base plate, an aluminum Twin Air PowerFlow cage, a unique pre-oiled domed air filter, and an ECU relocation bracket, which makes more room in the airbox. The Twin Air base plate replaces the slide-in stock KX250 airbox design and allows you to use the new Twin Air PowerFlow cage and filter. 

Unlike the KX450 PowerFlow kit, which uses rubber grommets, the KX250 PowerFlow kit uses a bolt that screws in by hand, like the previous 2024-and-earlier-model KX250 air filters. Also, this kit only works with the 2025–’26 KX250 PowerFlow air filter; the stock filter won’t work.

(3) Installation. Installing the system is far from straightforward. Twin Air provides a how-to video specifically for the KX450, which we recommend watching. It’s best to tackle this job in your garage rather than at the track. In brief, you’ll need to remove the subframe and take out the stock air-filter base plate, which is secured with several screws and bolts, before you can install the Twin Air setup.

(4) Performance. On the track, the power improvement was negligible. Our test riders didn’t notice a huge difference with the PowerFlow kit alone. However, the benefits are more about improving durability and confidence in your air filter rather than power. The Twin Air PowerFlow kit did stop dirt and dust from sneaking past the air filter and being sucked into the engine, which we’ve worried about ever since Kawasaki came out with this airbox.

WHAT’S THE SQUAWK? The installation takes time, so be patient and make sure to keep track of every bolt and screw you remove.

MXA RATING: The Twin Air PowerFlow kit isn’t designed to boost horsepower; it’s a durability upgrade. Its main purpose is to ensure a proper air filter seal to protect your engine from dirt and dust over the long haul. It’s an expensive upgrade, but the $360 spent is insurance for your engine.