I wanted to give you bLU cRU lovers out there some things that I really like on our 2026 Yamaha YZ250F. I am not going to sit here and type that all of these things are must haves. That will be up to you. You will also have to decide what part of your YZ250F needs to be addressed the most, if at all. These parts below are in no particular order and I didn’t put anything about suspension in here because there are hundreds of suspension shops you can get your stuff re-valved/re-sprung so if you want to know what I have tried that works, you can always email me at kris@keeferinctesting.com and I can help. If I sat and typed out every suspension company I have tried, I would be here for days so that is why there isn’t any suspension “must haves” on here. Yes, I do think the suspension can be better on the YZ250F. I also think it is a must have if you’re a lighter or heavier rider (the stock YZ250F suspension is built around a 160-185 pound Intermediate type rider). I do think once broken in, the suspension is a little soft for most riders over 185 pounds. If you’re spending money on any of this stuff below, you’re going to get your suspension re-valved so let’s move on.
Also, since we are on the subject of suspension/chassis, I haven’t tried any “races” on the 2026 YZ250F yet, but the FCP Race Cups have done wonders with my 2025-2026 YZ450F so take that for what it’s worth. The 2026 YZ250F and YZ450F DO NOT share the same frame, but the races do work for both, FYI.
XPR No Kinky Vent Hose Cap:
Chad at XPR is a smart human and it’s the little things that can make a person happy. Case in point is the No Kinky from XPR Motorsports. The Yamaha YZ250/450F gas cap vent hose sometimes gets kinked when the front part of the seat gets pressed down from the OEM dzus fastener. XPR now has an aluminum elbow that can rotate 360 degrees and ensure that your vent hose doesn’t get kinked while riding. No one wants their bike to shut off while they’re riding because of a vacuum problem so this eliminates that and is trick all at the same time! Winning! You can find these at xprmotorsports.com and they run $44.95
Dual Injector Kit:
I have ridden our 2025 Yamaha YZ250F in stock form this year and have noticed that it has lost some of that 2022 torque feel. It still has the most bottom end pulling power in class, but lacks some top end over-rev compared to the KTM, Triumph and Honda. It is most definitely a front side engine still that allows riders to short shift and lug if necessary. With the XPR dual injector kit the YZ250F now has more bottom end pulling power, more RPM response and more notably more top end/over-rev than I have felt in quite sometime. The YZ250F now has a distinct bark to it (with the help of the FMF 4.1 of course) and the rear wheel connection that you get is something that you will notice almost immediately. Third gear roll on power is more pronounced (even with the 13/49 gearing that we have) and the bike becomes more lugable, like it was in years past (2019-2022). The dual injector kit comes with a Vortex ECU like previously mentioned and with that comes pre-programmed XPR maps that ensure you get the proper tune for this kit. If you have your own Vortex, you can send that to XPR and they can tune it for the second injector kit.
This XPR dual injector kit (to me) is more noticeable than a full GYTR head/piston kit. With the GYTR kit you get more low to mid range pull, but I just don’t get that initial low end response/throttle crack like the dual injector kit has. The XPR dual injector kit makes the YZ250F feel lighter and more responsive than any other bolt on part that I have tried. I also feel with the stock engine, along with this dual injector kit, the YZ250F feels like it has more top end pulling power. Simply put this is one of the best engine mods you can do to your YZ250F without sacrificing much (if any durability). The kit by itself without ECU is 945.99 and with the dual injector kit, Vortex, Twin Air Powerflow kit is $2310.00. Pricey? Yes, but if you consider a muffler is around 1K and you get very little power, doubling that price and getting A LOT of power seems worth it to me, if you’re in the market to add some power to your bLU cRU. Tax refund? You know where to spend it now!
FMF 4.1 Muffler System
Although the stock exhaust is VERY hard to beat in terms of performance, it sounds like shit on the track. Sorry, but it’s true. The FMF 4.1 system slip on gives the bike a throaty tune and a factory look, but with a more tunable engine character. We have found that running the system without the spark arrestor insert takes away some back pressure, which causes the YZ250F to lose some of that bottom end power we want to keep on this bike. If you want to retain some of that back pressure/low end RPM response cu the spark arrestor out and install the insert.
The 4.1 adds mid range power as well with a little more top end pulling power. We prefer the system with the insert installed because it helps keep most of the stock bottom end, keeps the YZ250F quiet, and can even make it legal to ride on the trails (when spark arrestor screen is left in). You will lose use over a pound of weight when installing the FMF system (over the stock muffler) so that is another added bonus. The FMF system is made well but just be sure to keep up on the muffler packing (every 10 hours) and the canister will stay together longer. The longer you prolong re-packing the closer you get to burning up the can and possibly blowing out the rivets/etc. Oh and I almost forgot to mention that installing the FMF slip on is painless and takes five minutes of your day. Overall, I am happy with this FMF 4.1 slip on as it improved mid range/top end and made the YZ250F sound much better and didn’t sacrifice as much bottom end as I thought!
GUTS Wide Top Seat:
The Yamaha seat isn’t as bad as the Honda seat but to me it’s just not that friendly when pushing on the sides of the seat when cornering. The GUTS Racing “Wide Top” seat foam is more square than rounded and helps with feel on the bike as well as give your butt more comfort when riding the edges of your seat. With the stock seat, I found myself hitting the seat pan quite a bit under load (squatting into faces of jumps or hitting square edges out of corners) and this gave me pain within an hour or so of ride time. The GUTS Wide Top utilizes that more traditional box type shape which ensures a better/more friendly ride when seated. I am currently using the stock height “Wide Top” but GUTS offers taller foams as well for you Travis Preston types. The GUTS foam will not break down as quickly as the standard YZ250F foam, but I still recommend taking your seat off before you wash your bike! For $99.99 this is a must have if you want to be able to sit on the toilet the next day (after your ride) without cursing and scaring the hell out of your wife! Check it out over on gutsracing.com
Twin Air Power Flow Kit:
If you want to get rid of that plastic air filter cage system that sometimes doesn’t seal all that well on the 2025 YZ250F, go with the Twin Air Power Flow Filter Kit. To me the Twin Air YZ250F PowerFlow kit is the best all-around filter system for the YZ250F airbox. Why? With this kit, Twin Air replaces the stock air filter cage with an anodized aluminum cage (more durable), gets rid of the backfire screen (less restriction) for uninterrupted airflow and adds a small aluminum support bracket to hold the filter/cage in place. This ensures a more secure fit and doesn’t allow the filter/cage to float as much as the stock rubber strap piece that attaches to the filter/cage. The rubber strap is still utilized but the added security of that small bracket ensures that the filter cage doesn’t move or break the seal of the filter when accelerating. When accelerating the air volume/force that the 2025 YZ250F creates can possibly move the filter slightly and can break the filter’s seal around the lip.
This Twin Air design brings in more air via no restrictions caused by the backfire screen, better sealing around the edges and better throttle response/bottom end pulling power. Yes, that is right, you will notice more rpm response out of corners as well as better pulling power out of soft loamy berms. With the Twin Air Power Flow Kit along with some mapping, the 2025 YZ250F becomes a snappy, yet connected blue machine that gives the rider tons of rear wheel traction and enough excitement on low rpm that is helpful to get in and out of soft spots on the track.
The downside is that some dirt particles are still prone to fall into your air boot if you’re not careful with removing the dirty filter. The reason why it’s sucbseptble to dirt particles is because Twin Air doesn’t incorporate the backfire screen and unless you have a super steady hand, a few pieces of dirt can get down inside your air boot. Having the backfire screen on/in stock form isn’t going to help much if some of the dirt is near the edges of your cage/filter but having an open mouth cage is FOR SURE not going to save you if dirt gets though the filter so be sure to oil your filter properly.
If you do find yourself in that situation simply get a shop vac (with a skinny end/attachment) and suck out any particles that have found its way inside the air boot. If you DO NOT open/twist your throttle after the particles have found its way inside the air boot, you will get nothing past the throttle body and you’re engine will not get any dirt inside of it. The Twin Air Power Flow Kit takes a little more patience when changing filters, but can add power to your YZ450F as well as create a better sealing surface. You can also do what I do and simply lean the bike over on a stand then take your filter off and that will prevent any dirt getting too far into the air boot itself. BOOM! twinair.com
Works Connection Elite Throttle Tube:
Works Connection has been making throttle tubes for sometime now but we have yet to write a review about our experience with the product, so here we are! First, a lot of other brands are using a CNC-machined 6061-T6 aluminum throttle tube so that is nothing groundbreaking. This isn’t uncommon in aftermarket aluminum throttle tube world. Every factory bike in the pits has an aluminum throttle tube slid into a pair of handlebars to ensure there are no throttle failures when a crash arises. Works Connection uses one universal throttle tube combined with an assortment of interchangeable plastic cam pulleys to allow a single aluminum tube to be used on many different colored machines. The Elite throttle tube has a ball bearing mounted internally to lessen drag. Works Connection was able to combine all these technologies into their Elite throttle tube.
The snap-on thermoplastic pulley cams allow the Works Connection Elite throttle tube to work on all modern four-strokes. Each cam has a letter molded in it that signifies which model of bike it fits. What is nice about interchangeable cams is you can take it from bike to bike without having to purchase another tube as we have done this on our test bikes. The Works Connection Elite throttle tube rides on a sealed, ABEC-1+ rated, radial ball bearing and an internal polymer bushing. The combination of the bearing and bushing allows the throttle tube to ride above the handlebars in order to create a frictionless feel. Less contact between the two translates into less drag.We are not very smart people here at Keefer Inc. Testing but this seems to make sense.
The Works Connection throttle tube installs like a traditional throttle tube, but there are a few things you need to know. If you have handlebars with a larger than normal inner diameter, like Renthal TwinWall handlebars, you need to install the two supplied WC O-rings to take up the gap. Even with my novice mechanical skills as long as you read the directions and look at the throttle cams to ensure they are not on backwards you will be fine. If you want the same length of your handlebar bend/dimension you will have to cut 0.5 inches off the end of the right side of your handlebar. This 0.5 measurement is the measurement in which the bearing takes up space/length at the end of the tube.
What are some the unique points of the the WC Elite Throttle Tube? It has a smaller diameter feel to it than the standard G2 or ZRT tubes which to me is a nice feeling to the size of my large sized gloved hand. The WC tube is thin as well which doesn’t give the rider that rigid feel to the right palm on slap down or first bump touch. Some other aftermarket tubes make my right hand hurt or fall asleep because of the rigid nature of the tube. After speaking to Eric Phipps (owner of WC) he told me that they wanted to make sure the tube was as thin as it could be without sacrificing strength or durability, which I could feel when I rode with the WC Elite tube. For $74.95 it’s reasonably priced for an aftermarket tube and makes the action of the throttle buttery smooth. I mean one of the reasons you’re even considering an aftermarket tube is the action of the throttle right?
