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Only $10 for all 2026 SX, MX, and SMX series.
My kid just bought one for his x....let ya know in a couple weeks time.
I have it on my 23'
It's worth the money if you want a smoother transition onto the pipe.
It takes some of the explosivness out of the hit.
Thumpertalk has a few threads on the Hitlis with many points of view.
These Highland Hitlis videos may be of interest / use to the OP :
https://youtu.be/3gt33NZrvI8?list=PLajfmSUyZtZucKg4-eLM7D5sebcr3E0C-
https://youtu.be/Tt_H_WFpAiM?list=PLajfmSUyZtZucKg4-eLM7D5sebcr3E0C-
There's a fair few vids there on YZ250 mods etc - mainly Off Road / Enduro oriented..
I went through a thread on Thumpertalk that was 30 pages long and had the same couple people saying the same things over and over again 🤣
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Thanks, I’ll check them out.
Check out Cody Webb's recent build videos on YouTube. I believe he did an install and test of the Hitliss, along with a lot of other mods to modify the power on the YZ.
Thanks, I watched that already. It’s actually where I got the idea! 🤣
Weren't you just crapping on KTM for sucking because you have to "modify" the suspension to work?
But now you are gonna buy a YZ and have to completely modify the motor to make it run like a KTM?
Pick your poison I guess. 😉
This is so true. I have a '24 KTM 250xc, my son has a '24 YZ250X. I'm a longtime Yamaha guy but wanted electric start and to try the TBI bikes.
The KTM cost quite a bit more, still needs certian mods to run right (TSP head/TUNER), and the new spring forks are good but not great. The yz is cheaper, proven, very versatile.
If i ride the yz only for a day it's great, no real complaints. It can be modified to be whatever a guy wants it to be. But for me that KTM 250cc engine is just magic and riding back to back you really notice the vibrations and the abrupt power delivery of the yz. Hoping the Hitlis smooths it out and makes it more rideable like my KTM.
I'm just flipping agn5008 some shit, I actually love the YZ it's just hard to justify it for most off road riding for me these days given how refined the KTMs are for that application.
I still have, and always will have, two YZs in the stable. One steel framer (doesn't run currently) and one '07 aluminum framer.
I don’t have to completely modify the motor. The stock YZ motor is pretty dang good for racing HS. Obviously if you want to do hard enduro that will change some things. I can put an Apex or RK tech head on a YZ for a couple hundred dollars and I’m considering the Hitlis for another couple hundred and I’ll be good to go. The KTM you’re spending what, $3500 more right off the bat? Most people put a head on them as well. I’m not shitting on the KTMs. I’ve already said it, everything other than the suspension is great. And if I was doing hard enduro or trail riding then I would strongly consider another Austrian bike. It’s difficult for me to justify spending $3500 more right off the bat, then spending more to get the suspension where I want when I do your typical HS racing and single track. I do go do some hard enduro stuff with some friends so I’m sure on those days I’ll miss the KTM but I don’t do it enough to justify being unhappy with the KTM suspension.
We all need a little shit thrown at us every now and then. We’re just a couple crazy dirt bike guys who probably put entirely too much thought into making already good bikes even better 🤣
I’ve been a YZ guy for close to 20 years now. I genuinely love these bikes. I’ve built/used them for MX and various types of offroad, and have tried pretty much everything available for them (and countless combinations) over the years in an effort to figure out what suits me the best.
Years ago, I owned a few KTMs and one thing I really liked was the adjustable power valves. It’s something I always wanted to have on a YZ, but admittedly was never really capable of getting it done properly. So when the Hitlis came out, I ordered one immediately.
It absolutely works. Personally, I wouldn’t want it on a MX bike, but the tamed hit is absolutely positive in technical offroad sections, or places where traction may be limited. I will have it on any offroad YZ I ever own from here on out. I had to reassess my preferred offroad setup and start over. And the customer service from the guy who created it is second to none. He made the effort to reach out to me a few times afterwards to see what I thought, and make sure I was satisfied. Highly recommended.
All that being said, if you run it with an Apex XC head, or retarded ignition timing, you might find that it feels too slow. I’d run stock timing, and stock head/MX-type dome with the Hitlis.
What the hell are you spending $3,500 on? If it's any kind of protection parts you have to buy that for the YZ too.
I spent like $500 on a revalve for my '23 250xc and that's about it besides a skid plate and some rotor guards. Neither of which the YZ comes with, at least KTM gives you a janky skid plate to get you by if needed.
YZ comes with a moto tank too so that's another $200 - $400. Unless you are racing for the Overall in the AA class the larger tank on the KTM is good for most people.
I put one in after 5 or 10 hours on a 2024 YZ 250X and feel like it works great. A little bit more torque throughout the entire curve, more mid range, smoother, roll-on, and maybe more top end, although the X already has more over rev than the standard YZ.
Originally tried it with a GYTR flywheel, updated jetting, and an Apex XC head, and felt like it was a good improvement, but still didn’t feel like it had much power down low off the pipe. Stock it felt like it had no power down low, so the Hitlis helped, but the Apex XC head on an X doesn’t provide enough torque. I moved to their MX head (still less compression than the stock YZ 250) and that has been better, but also ended up doing a few other things.
I actually think the Hitlis would be even better on a YZ250 for moto, and you could leave the flywheel weight off, maybe, but take my feedback with a grain of salt as I mostly race off-road.
If I was riding an X and only could do limited motor updates, for me, I would do the Hitlis, MX head of some sort and quick turn throttle. YZ250 probably just Hitlis and v-force reeds.
I’ve got a thread going on all my updates to the bike and racing it here: https://www.thumpertalk.com/forums/topic/1496117-new-2025-yz250x/?do=ge…
I meant the KTM is $3500 more for the price of the bike. The stock KTM tank isn’t large enough for me to finish a 2 hour race either.
Thanks, that’s all great info. I was kind of in between in the XC and MX head. I’ll more than likely get both as well, but it sounds like the MX head may be better suited for me. I figured I’d reach out on here and see if any guys have experience with the Hitlis since thunpertalk seems to be the same 3-4 guys raving about it everywhere I’ve looked.
Copy.
I was thinking "this dudes crazy if he thinks a KTM needs $3,500 in mods to be raceable" 😂
Pit Row
I think the Hitlis has a much bigger effect than you expect, and that’s one of the reasons people get so excited about it.
A fly wheel is a little noticeable, and obviously you can change the port height and mess with the cylinder and get big changes, but many of those things don’t really smoothen the bike out or create torque without noticeable trade-offs. Yes, you can change the timing back-and-forth, but it also affects either and when you change it. Better bottom worse top end for example.
Hitlis sort of helps across the board and I don’t really see any downside unless you’re having someone build your motor professionally.
And unless you REALLY don’t want any power/torque down low or unless you’re really light or riding really casually I’d recommend staying away from the XC head. In fact if you buy an apex MX i’m happy to send you my XC insert to try. I probably will never use it again.
First...
You could try a fww and retarding the timing a few thousands before spending the coin on Hitlis.
7 thousands is stock, dial back to 3 or 4 and see how it works for you.
Also, jet it a bit on the rich side and run a #7 plug for trail use.
You can shim the pv spring preload a mm or 2, this has been controversial, some say it opens later but has a more abrupt hit.
But I think with the fww, timing and jetting changes, that should be toned down enough to be trail friendly.
We've got a couple rides on my son's 250x with Hitlis installed.
Riding western Oregon coast range single track. Mix of slow techy roots/rocks and flow trail up into third/fourth gear stuff. The Hitlis made a profound difference in power delivery. Extremely smooth and took pretty much all of the feeling out of the engine coming onto the pipe. My first thought was "oh no", it felt like it signed off way to early much like a Gnarly pipe.
There was one section of trail that three of us all swapped between the YZ and my KTM 250xc. Trail was fast uphill with sweeping turns but was hard pan clay that was pretty slick. The difference between the two bikes was very obvious. The YZ seemed to get traction and just motor up very confidently. The KTM just lit the rear tire up and was very hard to control. A couple days later the kid swapped on a one tooth bigger rear sprocket and brought 3rd gear into play much sooner which is nice because it just calms the bike down more and takes less shifting.
Really curious to get the bike on some faster desert trails but we won't be riding those until next fall but for the tighter woods it is so effective and easier to ride.
Have you thought of adding a Flywheel weight?
Flywheel weight is cheaper and easier to control. If you are looking to change the hit of power delivery, this is it. You will also gain lack of stalling in rocks, low, low rev riding and a more trials like bike.
https://www.steahlyoffroad.com/yamaha-yz-250-2003-2016-yz-250x-2016-fly…
Have you priced spoke skins since the tariffs hit?
Thanks for all the info. I’ve been checking out your thread on TT as well. I ordered the Hitlis today and already have a 9oz flywheel. I’m probably going to order the Apex head and MX dome as well. I most likely won’t even try the XC dome, it’s sounding like I won’t like that nearly as much.
I have the Hitlis system on a 24' 250YZx and, IMO, it's not needed for anyone racing above B level offroad, on an X model. The Hitlis mod works better on the std YZ, IMO. Between the lack of power in the midrange and the spacing between 2nd and 3rd gear on the X combined with the gearing I have to use (13/49) to get the bike to work for me, it almost negates the Hitlis. This is with using a 10.5 FWW and a 5UP (21cc) YZ cylinder head. It's good, but I wouldn't rave about it. In short, I'm not going any faster because I'm using it.
I've ridden an X with just a 13oz FWW, different gearing, and a 21.5cc head, and thought it was just as raceable as my bike, engine wise.
Did you go with the desert or woods Hitliss?
Awesome, I hope it works well for you. Quick recommendation, I would try the Hitlis first, then the flywheel second. That way you can make an informed decision on whether need them both or only need one.
Agree with Digger that’s the X’s need more power below the pipe and down low.
I actually already have the flywheel on my bike. I’ll definitely try it with and without after I get the Hitlis installed.
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