Been riding 2 strokes since I was a kid…30 years later I finally fully learn and understand how a power valve works

@StepstoPodium

7 ай бұрын

Glad I could help! 😄

This is a great explanation. I’ve always known what the power valve does, but I’ve never understood precisely how it does it until this video. Great job man.

@StepstoPodium

2 жыл бұрын

Thank you for watching! Glad I could help 😄🙌

@garydaniels1420

Жыл бұрын

Great straight forward explanation....how can I bolt one onto my trusted Honda C90...

@connorwilson8078

3 ай бұрын

Least you don’t think power band is a part😭

Best video on how power valves work

1:15 that was the best explanation of how 2 strokes work i have seen.

@StepstoPodium

2 жыл бұрын

Thank yoouuuuu 🙌

Now i understand what those different coloured KTM power valve springs do!

Great vid. Good to see some one going deep enough on the technical subject and not just scratching the surface of it. You deserve more traffic on your vids!

@StepstoPodium

2 жыл бұрын

Thank you so much John!! I really appreciate 😃🙌

excellent!! what actually opened and closed the exhaust valve (and what the stiff/soft springs do) was a complete mystery to me until now.

@StepstoPodium

2 жыл бұрын

Glad I could help 😁 little by little, a dirt bike becomes an understandable machine instead of something with leprechauns inside 😂

Great explanation of how a power valve works. I also enjoyed your videos on how suspension works. Please keep up the good work informing us!

@StepstoPodium

2 жыл бұрын

I appreciate it Stephen! Thank you so much for watching! 😄🙌💪

Thanks. Snowmobiles use a different exhaust valve, it’s a guillotine valve that slides up and down, but uses the same principle of restricting the exhaust port size at lower rpm and expands it at higher rpm. It was a total game changer for snowmobiles

Very nice description of the functionality of the power valve system! Knowledge is indeed Power. Gracias!

@StepstoPodium

2 жыл бұрын

Thank you so much Jeff!! 🙌😄

Great video! I just watched a few videos on this and yours was by far the best and easiest to understand!

@StepstoPodium

5 ай бұрын

Thank you so much!! 🙌

Rebuilding my first two stroke that has a power valve, this helped so much! Thank you!

@StepstoPodium

2 жыл бұрын

Glad I could help! 😄

I appreciate this in depth explanation.. I’ve recently just started wrenching on 2 stroke engines and this is the kind of stuff that’s helping to educate me.

@StepstoPodium

11 ай бұрын

Thank you for watching and glad to know! 😄🙌

Great video, and clear explanation, the addition of history to the tech is nice too.

@StepstoPodium

6 ай бұрын

We can't appreciate the technological evolution if we don't know where we started, right? 🙂 Thank you for watching!

I started racing go-karts in 1960, two stroke 100cc motors. We used crank case stuffers and dual carbs. Expansion chambers were not in use yet. Started racing MX in the 70s, two strokes again. Reed valves and x-chambers came along. Started racing SCCA sports cars after that and quit paying attention to two stroke development. Thanks for helping me get up to speed!

@StepstoPodium

7 ай бұрын

Thank you for watching! 😄

Great job again, keep up the fantastic work!

@StepstoPodium

Жыл бұрын

Thank yoou Nigel! I really appreciate it 💪🙌

That was the best explanation I’ve seen of how a power valve works.

@StepstoPodium

2 жыл бұрын

Thank you so much!😄🙌

Well said. Simple, precise and to the point.

@StepstoPodium

6 ай бұрын

Thank you for watching! 😄🙌

Great helped me out a lot definitely gonna share you to my other riders🙏🙏

@StepstoPodium

2 жыл бұрын

Thank you so much Ernie! 😄

You have some of the best "How motorcycles work" video's on youtube.

@StepstoPodium

2 жыл бұрын

Thank you so much man!! 🙌🙌💪

AMAZING VIDEO. Kudos to Yammy dudes for "Mo pOwA BAbAE"!

Talvez o canal mais Underrated de sempre 🙆🏼‍♂️ Obrigado pelos videos excelentes. 👍

@StepstoPodium

2 жыл бұрын

Muitíssimo obrigado Frederico! Obrigado eu por veres os videos 👌🙌💪

Well done, this helped me understand exactly what the PV does. I have a 99 KX500 and 2002 KDX200.

@StepstoPodium

2 жыл бұрын

Glad I could help! 🙂🙌

@MichaelSmith-pg6gi

Жыл бұрын

Those are great bikes. Have ridden both before.

Excellent, excellent, excellent (as always). The dynamic graphics really help and Indiana Jones is a nice touch :-) Obrigado pelo video

@StepstoPodium

2 жыл бұрын

Thank you Ariel! As always, never skipping a video! 😁 Top supporter 💪💪 (Thank you for your extra effort with the Portuguese language 🙌🙌)

I always wondered how a power valve works, not any more👌🏻

@StepstoPodium

7 ай бұрын

😁💪

Ai essas ilustrações... 🤤🤩 Muito bom como sempre! 💪

@StepstoPodium

2 жыл бұрын

Muito obrigado Zé! 😄 grande abraço 💪

Another brilliant video! Congrats

@StepstoPodium

2 жыл бұрын

Thank you so much Francisco! 😄💪💪

great video and great explanation, please do more!!

@StepstoPodium

2 жыл бұрын

Thank you!

Amazing video. Great teaching skills.

@StepstoPodium

Жыл бұрын

Thank you!!!

Great explanation! Enjoy your channel. -Nevada USA.

@StepstoPodium

2 жыл бұрын

Thank you Jake! 😄🙌

Thanks for the great explanation. For such a simple design, in appearance, the two stroke is a very complex system. Four stroke operation is easy to consider, but the resonances involved with a two stroke makes me think about the pulsejet engines.

@StepstoPodium

7 ай бұрын

Thank you!! 🙌😄

Great explanation.

Great video with easy to understand contents..

@StepstoPodium

Жыл бұрын

Thank you! 🙌

Awesome video. Thank you.

@StepstoPodium

6 ай бұрын

Thank you for watching 🙂💪

The original Yamaha YPVS used a rotary valve controlled by a servo motor and electronic control unit.

Another wicked video my man!

@StepstoPodium

2 жыл бұрын

Thank you so much man! I'm glad you enjoyed it 😄

Sooo smart to use centrifugal force 🤯 Great explanation man 🤙🏽

@StepstoPodium

Жыл бұрын

Thank you Tony! 🙌

Love the channel man thanks!

@StepstoPodium

7 ай бұрын

Thank you for watching! 😄

I had a 1984 Cagiva 125 without PV. Made about 10hp up to 7500 when, like a light switch, the hp went to 20+at 7600! It was impossible not to spin the tire, i tried many times. Made around 30hp but the power band was about 2000 rpm.

@Willy_Wanka

11 ай бұрын

Bro said a 1984 125cc bike without a power valve can make 30hp😭 more like 20 on a perfect day

@archiesweeney8267

11 ай бұрын

@Willy_Wanka not really, I've got a 1984 dt125lc and it makes about 24-25hp at 7-8k rpm

Before exhaust valve, some manufacturers were using rotary intake valve. I tried one Rotax with "enduro valving" and another with "mx valving" and there wasn't a jarring difference. Eventually all manufacturers went to reed valve and maybe an exhaust valve for power cases.

@awesomecooly123

Жыл бұрын

I have a kawasaki rotary valve enduro. The rotary valve has significant more torque on the bottom end compared to reeds. Reeds however have much better top end efficiency.

@redtobertshateshandles

7 ай бұрын

​@@awesomecooly123that's a trail bike.

@redtobertshateshandles

7 ай бұрын

My 250 Can Am MX which was road registered revved out superbly. Much better than a Japanese 250 MX. But bottom end was inferior. I guess the disc valve can be cut to have longer intake time.

Another aweosme vid!!

@StepstoPodium

Жыл бұрын

And some new ones are coming out really soon!!

Very well explained Cheers Mick

@StepstoPodium

Жыл бұрын

Thank you Mick! 👌✌️

Awesome video 👍🏻👍🏻👍🏻

@StepstoPodium

7 ай бұрын

thank you!!

Cool man u should do an explanation of the 4 brands and their differences thru time up to the present

I did not know about such a mechanism. Interesting.

@StepstoPodium

2 жыл бұрын

The more you know...! #knowledgeispower 😁

thank you!

Great video

@StepstoPodium

2 жыл бұрын

Thank you!

You're a genius! Thanks! 👌👌

@StepstoPodium

2 жыл бұрын

Thank you for watching! 🙌💪

Awesome vid thanks

@StepstoPodium

2 жыл бұрын

Thank you for watching! 😄

Brilliant..

brilliant!

@StepstoPodium

2 жыл бұрын

Thank you SteveH! 🙌👌😄

Thank you sir

@StepstoPodium

2 жыл бұрын

Thank you for watching! 😄

Bro, siempre te lo digo, pero tus vídeos som impresionantes. Sigue así!

@StepstoPodium

2 жыл бұрын

Muchissimas gracias tío! 🙏💪A ver si al final de algunos videos todos nosotros entendremos nuestras motos como si fuera una bici 😁

@mohamedshafeelmohamedbilal6364

2 жыл бұрын

@@StepstoPodium so less stif spring give high power in low rpm & more stif spring give high power in high rpm.?

@StepstoPodium

2 жыл бұрын

Not exactly. A stiffer spring will give you the impression of a higher power output because it will suffer a more abrupt power increase, but not a higher power output per se.

@mohamedshafeelmohamedbilal6364

2 жыл бұрын

@@StepstoPodium so your final answer is Default factory strength spring it give the best performance power Is it?

@StepstoPodium

2 жыл бұрын

It gives the most efficient power output and the desired one by the manufacturer. I would recommend adjusting the spring preload, but I wouldn't change the spring. They know what their doing 😄

Cool channel. I subscribed

@StepstoPodium

2 жыл бұрын

Thank you Tony! 😄🙌

How do we notice or determine if our motorbike has the powervalve issue? what are some symptom or signs?

@StepstoPodium

2 жыл бұрын

Very low performance through the whole power band!

The power valve is a vital upgrade but the revolutionary feature was adde earlier. That was the resonator exhaust which was made by a former v1 rocket engineer worked for the MZ in the motogp. Suzuki, which was the weakest brand in the gp for the time managed to get the resonator exhaust plans (they stole it throught the engineer and a young pilot borrowed from the mz..) after that suzuki became the unbeatabe brand for a decade. That was the key momentum, without the resonator the 2t was not stronger than a 4t with same displacement. With the new exhaust the engine was able to rev 2x higher and so producing almost double power. Now that wss revolutionary.

Wow now this was the best explanation i have ever heard and seen i have been looking for something like this really awesome stuff thank you big thumbs up 👍👍👍👍

@StepstoPodium

2 жыл бұрын

Thank you so much!!! Enjoy the channel! 😄🙌💪

@dirkventer8112

2 жыл бұрын

Hi love your channel got a question and i have asked around and done some research but no real solid answer i want to build a two stroke engine from scratch and yes re-engineering the wheel i know. But im battleing to get a awnser on why brush cutters uses flywheel /magneto and ignition but motorcycle!/bikes uses all that and a cdi if i build a performance two stroke and just ad a flywheel and ignition coil from a brush cutter, two stroke lawnmower, leaf blower wil it work? as mechanical things is easy but electronic things im not the brightest crayon in the boxs Just for the challenge my lower end is from a old kx 125 1985 thats is my base that im working from all the other stuff is missing... 😜

@StepstoPodium

2 жыл бұрын

I would love to answer properly that question but I included would have to make some digging prior about the matter 😛

@dirkventer8112

2 жыл бұрын

@@StepstoPodium awesome thank you keep the informative content coming we all learning here 👌

@StepstoPodium

2 жыл бұрын

I sure will!! 🙌🙌🙌💪💪💪

Buenas, tengo una yz125 1991,pero no tengo repuestos para la valbula de poder, el cilindro puede ser remplazado por el de alguna version mas nueva? asludos!

Sherco uses an electronically controlled motor driven system to actuate the power valve so you can change how it opens by reprogramming the ecu.

@StepstoPodium

2 жыл бұрын

Exactly 👌👌👌

Nice explanation, but if you permit the ypvs was electronically controlled by a servo motor. The kips system by kawasakie was a manual system. Great vid .

@StepstoPodium

7 ай бұрын

Thank you! 🙂 I'm almost certain thatcthe ypvs, or at least the first version of it, was fully mechanical. At the time of the making of the video I did an extensive research and don't remember having any ellectronics involved

Bro just taught me more in 6 mins than I did in 4 yrs of high school

@StepstoPodium

18 күн бұрын

Thaaaaank youuuuu

They opened the door for wider range power efficiency. The early attempts with actual Leprechauns proved difficult to maintain and impracticable. They were fine when not drinking but that didn’t last long. A governor system to provide control allowed to more precisely time the exhaust intake phases. That thing hooked up when it came on the pipe. A barking power band that liked to rev.

@StepstoPodium

7 ай бұрын

😂😂😂😂😂 loved the comment 👌😄

@user-yo1pk4ky4k

7 ай бұрын

That is the problem with Leprechauns, clever and amazing workers until they get a whiff of alcohol. That's why they had to remove all the Leprechauns who operated the power valves when ethanol fuels were introduced. When you find four Irishmen together, you will usually find a fifth!

The person who figured this out was a genius for his time.

@StepstoPodium

2 жыл бұрын

True indeed!

A DTR 125 e a TZR usavam uma valvula controlada por um motor electrico

The Jones family in the USA were the major development of the YZ's in the 70's, including the power valve.

@EarthSurferUSA

Жыл бұрын

The power valve did not hit Yamaha production until 1982. I think you have it confused with the reed valve.

@EarthSurferUSA

Жыл бұрын

The piston does not determine the intake timing in a reed valve engine, only a piston port engine used before the mid 70's. Would you like to consult with me before you make a historical vid? I am only 1 min in, and corrected you 3 times already.

Later on these became electronically controlled. Remember back in the 90's on my bike, when I turned the key, the valve cycled through it's motions.

Where can I buy the clip holding down the rod

So that is why bigger 2 strokes feel way smoother I was always used to tuned moped engines producing anything between 15-26hp, these engines are set up to give almost no low-mid end power and when it hits the powerband the difference is just brutal

Muito bom como sempre!!! Já agora o sistema da RCvalve da Honda não é bem igual pois não? Penso que que não dá para ajustar!

@StepstoPodium

2 жыл бұрын

Muito obrigado João! 💪 Assim de repente não estou a ver qual sistema é 😛

@wolftracks2033

2 жыл бұрын

@@StepstoPodium è o sistema Powervalve das Hondas CR250 2T que penso que seja eletrónico e que não é possível ajustar.

How to set squares for Hero Hunda

Show ✌🏾

@StepstoPodium

2 жыл бұрын

🙌🙌🙌💪😊

Can you do a video about TPI vs TBI? And electronic power valve?

@StepstoPodium

Жыл бұрын

Eventually, yes 😅 the EPV is definitely on the radar. Just waiting for the conditions to meet 😁👀

Anyone else think he sounds like borat? Good video by the way.

@StepstoPodium

6 ай бұрын

🙄😂 Thanks!!

I believe it has more to do with port timing than port size

So, on GasGas Ec300 to delay the PV I need a harder spring, not just a screw adjustment, right? :)

@StepstoPodium

Жыл бұрын

If you don't have an adjustment screw, yes!

Thanks. Looking at your graphs: if increasing preload for more progressive power has the effect of reducing low/mid range with no benefit on the top end power, who would use it and why? Cheers.

@StepstoPodium

4 ай бұрын

Some applications/riding requires a more snappy feel or response of the engine! Not necessarly a bad thing, simply different

@miro_s

4 ай бұрын

@@StepstoPodium so, would you say mx wants snappy power with the idea of keeping it always in the power band (and perhaps for jumps?) while enduro wants more linear power for control at low rpms?

@StepstoPodium

4 ай бұрын

@miro_s exactly!

I enjoyed your governer joke, good vidio thanks for the explenation.

@StepstoPodium

7 ай бұрын

Thank you 🙂🙌

I understand everything except one thing. When the fresh gasses are let into the combustion chamber, some of it escapes into the exhaust port, as is demonstrated in the video. However, it looks like the exhaust gasses are pushing them back into the chamber. What causes this? How can the exhaust gasses just reverse themselves? Aren't they supposed to flow straight out of their port and not flow backwards?

@StepstoPodium

2 жыл бұрын

It's all thanks to the back pressure wave. I've got another video clearing that out 😄👌

@rostifardian

Жыл бұрын

It’s the reason that 2 strokes have their fat pipes. Exhaust fills the expansion chamber then gets choked way down at the back, so the exhaust pulses bounce back toward the engine and that bounce back pushes the unburned fuel back into the combustion chamber

How have the design of power valves evolved since then up until modern bikes like KTM? Are they more complicated now or still the same as your video?

@StepstoPodium

5 ай бұрын

Fairly similar :)

Like a Vtec , interesting

Now I know Centrifugal force are so useful in 11th I thought that why it's useful 😂

Com os preços da gasolina, se também tivesse mos de alimentar um doente pqp! Qualidade sempre #1!

@StepstoPodium

2 жыл бұрын

🤣🤣🤣🤣🤣🤣

My friend passed away when this velve open on kawasaki 150 ss , gas cable stuck and cant go back at 140 km / hour and more faster and faster , its happen quick no time to react or thinking , so first instinc was push back brake and lose ballance then he fell off

@StepstoPodium

Жыл бұрын

Sorry to hear that Sheldon 🙏

In Yamaha we Trust 🙏!

Yamaha TZM-150 legendary YPVS

Soo' thats! Power valve aaa litle Bit Like the secound caburator by the exoud- oud Port.

you are like ibrahimovic

What difference between power valve and reed valve

@rostifardian

Жыл бұрын

Power valve is an exhaust tuning technology. Reed valve is a 1 way check valve to allow fuel into the engine from the carburetor.

Resonance

Your videos are great. This is almost like steam engine technology balls out

@StepstoPodium

7 ай бұрын

Thank you!! It's really simple, yeah :)

The only reason 2strokes are gutless at low rpm is they're purposely deprived of air flow.. That's all the ''power band'' is doing it just lets the engine actually take a gulp of air .

kzread.info/dash/bejne/iolko6SlnKiYZrw.html to adjust in optium, not too much or less. If you soften too much I think the motor can stop. Becasue its not convenient to open everything. To open pnly in a distinct rp. And how much needed

i still say it's black magic vodoo withcraftery is how the power valve works.😅.lol.

@StepstoPodium

6 ай бұрын

Hopefully after the video it's just black magic voodoo 😂

Thank you to Yamaha.

Understanding how it works wasn't a complete mystery for me but boy can I get inside there for spring tuning ☹ that's a no no

@StepstoPodium

2 жыл бұрын

It depends which bike you're tuning, but there are bikes that do not allow any adjustability 😛

@bodyfitnessworkouts7210

2 жыл бұрын

@@StepstoPodium yz 125 1992

The power valve is about timing, not the size of the exhaust port.

@StepstoPodium

Жыл бұрын

The size determines timing

@openidqd

Жыл бұрын

@@StepstoPodium Not size, but location. more precisely - the location of the upper edge of the exhaust window - the angle of its opening. this is what ypvs regulates. True, this is already boring on my part, but in the past, such an explanation, your explanation, misinformed me for years.

@openidqd

Жыл бұрын

@@StepstoPodium для будущих поколений оставлю объяснение от Yamaha технологии ypvs: kzread.info/dash/bejne/Zp95tNWqe6afgZc.html

I've heard mechanics suggesting to just keep the powervalve open at all times by thread locking the mechanism and removing some parts. Do you think it's a good idea?

@StepstoPodium

2 жыл бұрын

Nop 😂 why would you do this?

It's definitely not a turbo, but it feels like one 😅

@StepstoPodium

2 ай бұрын

Agree!!

@NoName-gu9tf

2 ай бұрын

@StepstoPodium was on a YZ85, and I was very impressed at how quick it was and the fact it would destroy my crf250x

The power valve, if designed well, does widen the power curve a bit, but does not maximize the power at the lower rpm's because the pipe effects are only great for a fairly low range of rpm, and that depends on the tuned length of the fixed pipe. If a guy in the comments section educated the channel more, it is time for you to do more homework.

First off, I politely disagree. The port timing, the holes in the cylinder, a- "PRE PROGRAMMED PERFORMANCE CURVE, Is what controls it. The piston only ENABLES this performance curve. Proof? CHANGE THE PISTON ALL YOU WANT- won't change by much. Change toe port size and timing in the cylinder- and your world changes!