Just took it out on the first ride absolutely love the power delivery, still pulls just as hard but without the abrupt hit and my clutch is rarely needed now. I've been on YZ250s since 2011 and this is a great mod, in all honesty I come from a motocross background and this would work well for traction and power delivery in long motos.

The Hitlis power valve was one of the best modifications I ever did to my YZ. I have been racing hard enduro, hair scrambles, and endurocross for years now. The control over the YZ that Hitlis has given me will forever change how I race. I especially notice how this changed loading up the flywheel to propel my-self over obstacles in endurocross. The traction has improved drastically because my tire doesn't break free when I hit the power band anymore. Tim was a great help with install, his videos make the install easy. If you are holding back because of the price you don't know what you are missing out on. This mod has to be the most bang for buck engine mod that you can put on one of these bikes. Shortly put, if you don't have the Hitlis on your YZ you are really missing out.

I actually did a video on this product and I really wish this would have been around when I first had the YZ250: https://www.youtube.com/watch?v=vNxSZa9Fmx4&t=1s

The hit on the YZ turns into controllable pull from bottom to top, you don't really lose anything on top you just get there in a more predictable fashion. The bike doesn't become more 4 stroke like it's more of a feeling like a mix between the power curve of a TPI and a TBI KTM.

The installation is fairly easy and the install videos cover every conceivable encounter you may face installing the product. Also the support and insight from the developer along with their interest in following up with users of the Hitlis system is refreshing as it is helpful.

I would put this improvement as one of the most dramatic changes you can do to your bike off the bat and highly recommend it.

Took about a 1hr to install. Everything when smooth. I suggest get a set of extra gaskets. And governor bearings. Just incase. Taking it out on my first ride I could tell instantly the smooth power delivery. I do a lot of hard enduro riding. And finding traction and control the bike is a lot easier. 100% a must on a YZ250X

Well for anyone who is interested in a YZ295 BB Hitlis review here's one: The HITLIS set up is awesome! It is noticeably healther off the bottom/mid and provides impressive overrev. In summary the bike feels 10lbs lighter cuz it just responds so effortlessly with strong power thru the entire RPM range. I don't know what to say but it's so impressive, respectfull power but so predictable and linear. For example on a decent cat litter deep DG climb behind my buddy on a KTM 350 EXC-F Six Days with the same rear tire both at 12 psi, the YZ closed in and had to pass at the top of the climb cuz the HITLIS was pulling 4th gear tractoring while the 350 was searching for grip. I find this set up so impressive with a combination of super responsive throttle response for blipping doubles over random whoops or rock/log features while a gear higher than usual to just rolling the power on a climb or straight and the front end just hovers, with predictable coorelation to the right wrist. I've got over 70 hours and counting on my HITLIS 295. So impressed with the useable power, and reliability. When you want the bike to do something and it just response without hesitation and the performance becomes an organic extention of your intentions... that's a game changer for me! Sorry for the ramble but it's pretty sik and I needed to tell someone... Thanks to the crew at Productive Power... the future looks bright!