I really enjoy your videos. Thank you. I also ride under the power band, just enjoying technical mountain trails at a leisure pace.

I believe with less tension, it will actuate sooner, which will open the exhaust port more. I haven't looked at how exactly it works, but on 2 stroke snowmobiles they have a similar setup, either mechanically actuated or with crank case pressure. Low rpm, a small gate will make the exhaust port smaller, once you're almost at the power band, the gate opens, allowing full size of the exhaust port. What i think is that the exhaust port with the power valve closed, actually restricts exhaust flow, so when lugging, the engine would benefit from the exhaust port opening sooner. I may be wrong but this is how i assume it's working.

I've been doing this for 30+ years now to YZ250 Engines. Actually used a different spring, to the same results! To really enjoy this modification, install 12 ounces of weight to the flywheel also and it will really pull out of corners!

Thank you for the video, well done. My water pump seal just went out so I'm going to do this mod while I have the cover off.

Fantastic! Thanks for taking the time to get this online.

Great vid thank you, idk how im just finding out about this iv had my 2017 yz250x for a little over a year.

You need more tension by chiming the spring to slow down the power band. On ktm they sell you a stiffer spring for that

Thank you sir ! your video was vary good and you are vary good at talking and explaining things thank you again !

This vid was a great help. Thank you

Put a lectron on and made it feel like a 300 2t. Vforce reeds. Gnarly pipe. Fmf spark arrestor. 9oz flywheel 13/52 gearing. Ride single track 2nd/3rd. 5th top speed is 105kmh. 3800ft 20c. Bibs

Hawz zit! I think you it have backwards! The balls in the PV have to overcome the spring pressure to activate the power valve. Same as KTM a use lighter/ heavier springs to bring the PV on earlier/ later. Overall power will be the same, all that's changing is when the PV opens. It just gives the rider a wider range of softer power. Delaying when the PV opens to soften the bottem end does have the effect of when it does open, the hit comes harder and more abruptly.

just did my 2016! thanks for the vid im just here to flex that i compressed my PV with one hand. confirmed samurai

Man I was struggling with jetting and air screw mix and always seemed to be gutless on the low end of second and third, Especially noticeable on long steep hill climbs no amount of clutch feathering would help bring the rpms back up to where I needed them. I removed that little washer in the governor and bam tons of low end power/torque in 2nd and 3rd, Slow roll hillclimbs are no problem on the x now, she feels like a different bike on the low end. It also helped with some of the low speed stalling that was frustrating me to no end, My wimpy clutch hand cant thank you enough. So glad I found this video before I went and spent a bunch of money on a flywheel weight. Thanks for putting this out there and helping a gumby rider like me from banging my head against the wall. P.S i dropped the ball bearings like an idiot even though you specifically warned us...

I would not be surprised to find that the washer you removed is hardened, close to the hardness of the bearings, and the collar the bearings ride on after removing the washer is not as hard. If that is the case, you will probably find some wear on the collar after a good amount of riding time. But it is a cheap enough part to replace every year if needed. I am not sure that opening the valve earlier is what i want to do. I want more low end power, and what lesser spring tension should do is let the valve open up earlier, which will probably mellow out the power at the point the valve normally opens up, extending mellow power a few hundred more rpm's, (until the piston speed matches the taller port more efficiently). I do build small 2-stroke engines for a living, but I am not totally sure about that.

There is a easier way to achieve this without taking it all apart. You just pull the cover off and connect a spring to the actuator arm. This will release preload force on the internal powervalve spring. Old timers i saw do this trick would drill a small hole in the top of the case right above the actuator, put a cotter pin up through the hole from the bottom and bend the tabs over so it cannot pull down into the case. Get a small spring the correct length with hooks on both ends. Connect the hook on one end to the arm and the other end to the cotter pin loop. The best part about the mod is you can quickly change springs allowing you to try different springs lengths and strengths until you find what works best for you. Also with this mod you can easily change springs when going from mx to trail riding. No need to pull the whole powervalve out. I will point out that your powervalve actually does create power slightly. Modding it in any way doesnt just change the power curve. If you adjust it for woods riding by taking away the "hit" you are actually losing power. Essentially governing the bike for smoother feeling delivery. Dyno testing shows you can change your power output to the wheel by +/- 5hp by simply changing springs on a 250cc.

Do a hardness test on the washer and then the collar. if the collar is much softer then maybe a weaker spring is the better option.

The ktm’s come with 3 different power valve springs. The lighter gauge springs make for a snappier throttle and bigger hit.

As a fellow YZ250X owner I've been really struggling with getting the flat spot out of the upper-mid range as well as the lack of snappy power off the bottom. Needless to say, I'll be doing this mod this weekend! I really appreciate the videos man, there isn't enough information out there on the X, good on you for giving a little! I subscribed. I have a few vids on my channel with the X if you're interested. Cheers from the USA.

Thank you brother, much appreciated

Float height, jetting, pv mod Provided 3x the gain on a pipe and rad valve. I have both the gnarly and dep pipe.

Could u take out the other washer on the tail end that also is against a collar??

The thing I was concerned about is what is the collar made from steal or ally

Replace the spring with a after market spring for GREAT results. Checkout the Cisco's Power Valve Spring.

Have you disarmed to check that the modification has not caused any damage?

This is exactly the same as turning the dolly screw out a bit on the KTMs. JD has done extensive Dyno testing and found a little bit like this washer makes the power more linear w/o losing any power. Too far and it detunes again. The “Hit” if from PV not opening as soon and then Bam! I wonder if I can do same mod on my 125x?

Hey mate, do you have remove the side of the case like you have to adjust that governer? I’ve got a 2011 YZ250 that I’m setting up for enduro. Can’t decide whether to do this mod to soften the power or add a heavier flywheel weight. Any help is much appreciated!

The best mods are a head recut/rechamber, Pv mod and jetting. That is where the power is. Forget about pipes, silencers and reed blocks.

Has anyone tried this on a standard Yz250? Also do you remove 1 #6 washer or both #6 washers?

If I followed correct you reduced the preload on the spring and allow the power valve to open sooner?

Is there any concern with the metallurgy between the washer and the collar? The washer is part of the bearing and as a result “made” for that application vs the collar not being a point of friction???

Thank you. Just found out about this and I think I am doing this to my YZ to make it more woods worthy.

I honestly love the South African accent lol

Did it work

Just a question! do you think you could shorten (cut the spring smaller) the spring shorter instead of removing a washer that is there for a reason?

will it give a better mpg or not because i do long run trail and i don’t want to ruin my mpg doing this mod

Thanks for doing this!! How do you like it?

I love the jokes

Will this work on a Yz125x as well?

As someone mentioned, removing the washer will creat less spring tension on the governor...which...ineffect would allow the pv to open sooner, at a lower rpm. I would think adding another washer is what you want to do. Adding a washer would place more preload on the spring, which would cause the governor to open later / higher rpm....giving the bike a little more lugging power/ low end. I think you have the mod backwards.

So after you did this mod could you tell the difference ?

Just get a softer spring