"Hitlis" powervalve system

[ponder]

3 hours ago, yzScott118 said:

Curious if there are any gains with this, i've heard fatty on the stock 250X isn't good. Thanks!

You not thinking of the Gnarly perhaps?

[yzScott118]

1 hour ago, ponder said:

You not thinking of the Gnarly perhaps?

No

[Fun Police]

On 3/13/2025 at 10:35 AM, yzScott118 said:

Anyone running a FMF fatty with the yz250X with the standard YZ cylinder head and hitlis? Curious if there are any gains with this, i've heard fatty on the stock 250X isn't good. Thanks!

I tried one and took it off after two rides. Made the low end too lazy.

I've got a high comp head and a light/medium flywheel weight, so not completely stock

[ponder]

 

[rafael]

Hello. I have yz250x 2025 stock. If i put the hitlis.

1.Do i need to add anything else ? 

2.is the gytr flywheel necessary ?

3.gasoline consumptuon is higher ?

 

Thanks

Hello. I have yz250x 2025 stock. If i put the hitlis.

1.Do i need to add anything else ? 

2.is the gytr flywheel necessary ?

3.gasoline consumption is higher ?

 

Thanks

[Otto Kirk]

1 minute ago, rafael said:

Hello. I have yz250x 2025 stock. If i put the hitlis.

1.Do i need to add anything else ? 

2.is the gytr flywheel necessary ?

3.gasoline consumptuon is higher ?

 

Thanks

Hello. I have yz250x 2025 stock. If i put the hitlis.

1.Do i need to add anything else ? 

2.is the gytr flywheel necessary ?

3.gasoline consumption is higher ?

 

Thanks

Leave it stawk and use the suggested leaner power jet suggested by HITLIS.

Many users remove the go-to mods.

[FAT N SLOW]

7 hours ago, rafael said:

Hello. I have yz250x 2025 stock. If i put the hitlis.

1.Do i need to add anything else ? 

2.is the gytr flywheel necessary ?

3.gasoline consumptuon is higher ?

 

Thanks

Hello. I have yz250x 2025 stock. If i put the hitlis.

1.Do i need to add anything else ? 

2.is the gytr flywheel necessary ?

3.gasoline consumption is higher ?

 

Thanks

I am on a stock bike with Hitlis desert kit. I absolutely love it. The only difference in fuel consumption I have noticed is from correcting my float hight and getting the jetting right. I use a lot less now. Stall less on downhills and have a stronger cleaner pull under acceleration 

[Drn]

10 hours ago, rafael said:

Hello. I have yz250x 2025 stock. If i put the hitlis.

1.Do i need to add anything else ? 

2.is the gytr flywheel necessary ?

3.gasoline consumptuon is higher ?

 

Thanks

Hello. I have yz250x 2025 stock. If i put the hitlis.

1.Do i need to add anything else ? 

2.is the gytr flywheel necessary ?

3.gasoline consumption is higher ?

 

Thanks

Do you “need” anything else? No. Do the jetting recommendations for sure.
I have a 2024 250x and I put on a gytr flywheel. I like it. 
 

The Hitlis is the real game changer. Love it.

Edited April 20 by Drn

[Maxx444]

Found a non JIS machine screw for the side power valve covers.

[MitchPeters]

My first impression is Wow! It seems to come on a lot lower and just pulls to the top. Installation was straight forward. Good videos. Parts made well. I have 1 harescramble and 1 lap of a complete mud harescramble on it. Hopefully Sunday will be another good test. I highly recommend the Hitlis.

[Drn]

7 minutes ago, MitchPeters said:

My first impression is Wow! It seems to come on a lot lower and just pulls to the top. Installation was straight forward. Good videos. Parts made well. I have 1 harescramble and 1 lap of a complete mud harescramble on it. Hopefully Sunday will be another good test. I highly recommend the Hitlis.

Welcome to the club!

[Fun Police]

On 6/18/2024 at 6:27 PM, YAMAHA NICK said:

The gnarly doesn’t fall off with the Hitlis like it did prior.

still does but not as badly at all 😉

 

I'm in tight rocky season now and I like it with the hitlis. With the high comp head I've got it was too punchy stock. Imma leave the gnarly on for the summer in the high elevation stuff

[yzScott118]

On 4/25/2025 at 2:57 PM, Maxx444 said:

Found a non JIS machine screw for the side power valve covers.

Why would you do that

[Cameron P]

Coulda just bought a JIS screwdriver. The Vessel Impacta would back that right out every time. 

[Maxx444]

On 5/25/2025 at 7:39 AM, yzScott118 said:

Why would you do that

No more fuss with JIS. All gone except for brake reservoir. Which I'll probably do too. Who knows....

Easier to fix trail side.

[Maxx444]

6 hours ago, Cameron P said:

Coulda just bought a JIS screwdriver. The Vessel Impacta would back that right out every time. 

Not carry that in my backpack. Thank you, though. 

[suckbangblow]

1 hour ago, Maxx444 said:

Not carry that in my backpack. Thank you, though. 

Changing out your power valves mid ride?

[Maxx444]

Before Hitlis, had this little guy stuck in the bottom. Hanging up the power valve. 

So anything is possible. Hopefully not anymore though... fingers crossed.

Yes that's an old pic prior to Hitlis install with cap screws and bolts. Vs JIS screws.

Edited May 26 by Maxx444

[moto9]

Another crazy idea I had was to fabricate a spring preolad adjuster that sits on top of the flapper valve with the adjuster mechanism on the top of the cover.

You could adjust for conditions, mild to wild.

If I had a lathe, mill and tig...I'd be experimenting with the project.

 

[HERA]

1 hour ago, moto9 said:

Another crazy idea I had was to fabricate a spring preolad adjuster that sits on top of the flapper valve with the adjuster mechanism on the top of the cover.

You could adjust for conditions, mild to wild.

If I had a lathe, mill and tig...I'd be experimenting with the project.

 

It is a great idea... I have already done it.  This simple mod idea comes with a few  inherent issues.. Still can be effective but it really is not necessary for a good running engine/PV set-up

The stock PV design, while vintage, still gets the job done fairly well. Especially for those of us that are not Pro Level Hard Enduro Riders.

The issue is in the engine's power-band and carb set up.. Once you address those, the bike takes on a whole new personality