The Yamaha YZ250 is riding the crest of a popularity wave at the moment. Enduro21 looks at the HITLIS power valve kit, tailoring the mighty 250 two-stroke for enduro and woods riding.

Productive Power or just simply Tim, as literally everyone who Enduro21 has spoken to about the Hitlis, is one of those companies whose specialist knowledge in a particular bike is worth its weight in gold.

In this case, more than any, there’s no question the passion is for the YZ, and although there’s an inherent appreciation of Yamaha’s work, the focus is on making something good, even more fit for purpose.

With the Yamaha YZ250 being designed for motocross, even the X model, that purpose is hampered by problems with the original equipment and its engine tune, which makes life harder than it should be for enduro riding.

How the YZ250 makes its power is something Enduro21 is no stranger to and has tried and tested many options, including flywheel weights, different exhaust systems, and more or less base gaskets.

The Hitlis, however, promises next-level attention to the YZ power valve, making power delivery smoother, less peaky, and providing more feel and traction.

The next level

Made for the Yamaha YZ250 and YZ250X, with a 100% money-back guarantee and global shipping…these are all solid consumer-focused statements staring you in the face when you click on Hitlis.com.

What you can’t immediately see, but which immediately comes across when you start to speak with Tim, is the passion and knowledge, and that goes a long way in this consumer-driven world.

That was a solid reason why Enduro21 reached out to Productive Power to understand more about the Hitlis, along with a strong recommendation from Cody Webb for the benefits of installing the system to his YZ.

What is it and what does it do to the YZ?

Essentially, Hitlis is a kit which replaces all the parts from the power valve in all YZ250 engines (two-stoke) from 1999 until now. The Hitlis design switches out many of the OEM parts for those which you can see in the kit.

The OEM power valve, which is designed to deliver a hit of power like you’d expect from a motocross two-stroke, uses spring resistance against the valve opening.

What works on a moto track can be detrimental in between the trees and for those of us who love the YZ, having better feel from the throttle to the back wheel is something craved.

Hitlis works primarily by putting “the governor back in control of the engine”, rather than making the rather more crude spring do the work. It creates a different valve sequence to smooth out the power curve, making a more gradual approach to the same power which will help so much in enduro.

It’s adjustable to suit desert racing or woods enduro, with Productive Power describing the difference simply as; do you normally ride in second gear or fourth gear? Desert is the faster one, woods is for the slower stuff.

Machined quality

All parts are made in the US using the highest quality methods and materials available, they tell us. The precision machined parts are all hardened tool steel, thrust washers are 1095 blue temperate steel, and the springs are all commercial grade chrome silicon. The spring and shims allow the Hitlis governor to be adjusted so you can set it up as mellow or as aggressive as you prefer.

Is it easy to install?

The small box of bits coming in the post, and the fact you need to do some moderately invasive surgery on your cylinder head, is either a daunting prospect or (as in our case) part of the very reason why we love our dirt bikes and, in particular, the YZ. It means doing something meaningful to actively improve your bike, and we like that.

Installation guides on their YouTube channel are easy to follow (there are different versions, and a ‘how to adjust the governor’ is on there too), and you’ll also find you’re not the first to fit one, which means there are many tutorials to read and watch online. Not least from the Productive Power themselves, who are more than ready to assist if you reach out.

This kit will go on our much-cherished YZ, which we’ll follow with a “how to” installation feature and obviously testing on E21 ASAP, so stay tuned.

 
Cost: $375/£302/€363.95 plus shipping
Contact: www.productivepowerllc.com

Photo Credit: Enduro21