How the Power Valve works | Offroad Engineered

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  • Опубліковано 5 лют 2025

КОМЕНТАРІ • 213

  • @P2Feener305
    @P2Feener305 Рік тому +13

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

  • @rideroftheweek
    @rideroftheweek 2 роки тому +73

    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
      @StepstoPodium  2 роки тому +4

      Thank you for watching! Glad I could help 😄🙌

    • @garydaniels1420
      @garydaniels1420 2 роки тому

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

    • @connorwilson8078
      @connorwilson8078 10 місяців тому

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

  • @CobroxYT
    @CobroxYT 11 днів тому

    finally someone who actually explains what engages the powervalve! very well explained thank you

  • @socks2441
    @socks2441 2 роки тому +16

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

  • @tedecker
    @tedecker Рік тому +2

    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!

  • @cannerfelt
    @cannerfelt 3 роки тому +36

    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
      @StepstoPodium  3 роки тому +5

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

  • @PurryKitchenWithTaste
    @PurryKitchenWithTaste 9 місяців тому +4

    Best video on how power valves work

  • @TWDStroke
    @TWDStroke Рік тому +4

    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
      @StepstoPodium  Рік тому +2

      Thank you for watching and glad to know! 😄🙌

  • @willjones7132
    @willjones7132 Рік тому +1

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

    • @StepstoPodium
      @StepstoPodium  Рік тому +1

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

  • @knutejay
    @knutejay 3 роки тому +11

    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
      @StepstoPodium  3 роки тому +3

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

  • @UpNortBassin
    @UpNortBassin 2 роки тому +2

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

  • @jimssawsnstuff8903
    @jimssawsnstuff8903 Рік тому

    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

  • @screemingturbo8806
    @screemingturbo8806 2 роки тому +1

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

  • @Rakkasan-vr8xt
    @Rakkasan-vr8xt 2 роки тому +3

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

  • @Jtm7708
    @Jtm7708 2 роки тому +2

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

  • @nvmcrider8475
    @nvmcrider8475 3 роки тому +1

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

  • @paulturner8180
    @paulturner8180 Місяць тому

    Fantastic video. Great explanation, thanks 👍

  • @markusdelirious
    @markusdelirious Рік тому

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

  • @One-Track_Dynamic
    @One-Track_Dynamic 3 роки тому +3

    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
      @StepstoPodium  3 роки тому +1

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

  • @robocombo
    @robocombo Рік тому +2

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

  • @tonyrichengod9280
    @tonyrichengod9280 Рік тому +1

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

  • @jakeb92980
    @jakeb92980 3 роки тому +1

    Great explanation! Enjoy your channel. -Nevada USA.

  • @MotoDeSoto
    @MotoDeSoto 2 роки тому

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

  • @Dannysoutherner
    @Dannysoutherner Рік тому

    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.

  • @nigel2447
    @nigel2447 2 роки тому +1

    Great job again, keep up the fantastic work!

    • @StepstoPodium
      @StepstoPodium  2 роки тому

      Thank yoou Nigel! I really appreciate it 💪🙌

  • @kevowski
    @kevowski Рік тому +1

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

  • @yorkchris10
    @yorkchris10 3 роки тому +4

    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
      @awesomecooly123 2 роки тому +2

      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
      @redtobertshateshandles Рік тому

      ​@@awesomecooly123that's a trail bike.

    • @redtobertshateshandles
      @redtobertshateshandles Рік тому

      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.

  • @LChem1
    @LChem1 2 роки тому +6

    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
      @Willy_Wanka Рік тому +1

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

    • @archiesweeney8267
      @archiesweeney8267 Рік тому

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

  • @Nachette10
    @Nachette10 3 роки тому +1

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

    • @StepstoPodium
      @StepstoPodium  3 роки тому

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

    • @mohamedshafeelmohamedbilal6364
      @mohamedshafeelmohamedbilal6364 3 роки тому

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

    • @StepstoPodium
      @StepstoPodium  3 роки тому

      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
      @mohamedshafeelmohamedbilal6364 3 роки тому

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

    • @StepstoPodium
      @StepstoPodium  3 роки тому

      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 😄

  • @thehonestmechanic
    @thehonestmechanic Рік тому

    Well said. Simple, precise and to the point.

  • @be007
    @be007 Місяць тому

    nice explanation! thanks
    cheers
    ben

  • @dalepiwek
    @dalepiwek Рік тому

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

  • @fredericodias1
    @fredericodias1 3 роки тому

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

    • @StepstoPodium
      @StepstoPodium  3 роки тому

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

  • @tonycerino1736
    @tonycerino1736 2 роки тому

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

  • @erniedesimone3191
    @erniedesimone3191 2 роки тому

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

  • @globyboulga1045
    @globyboulga1045 2 роки тому

    Amazing video. Great teaching skills.

  • @250txc
    @250txc Рік тому

    Great video with easy to understand contents..

  • @bobbygetsbanned6049
    @bobbygetsbanned6049 Рік тому

    Great explanation.

  • @acepilotson3331
    @acepilotson3331 Рік тому

    Awesome video. Thank you.

  • @rico8089
    @rico8089 Рік тому

    Awesome video 👍🏻👍🏻👍🏻

  • @IanDarley
    @IanDarley 2 роки тому +2

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

  • @AntiStressKit
    @AntiStressKit 3 роки тому

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

    • @StepstoPodium
      @StepstoPodium  3 роки тому +1

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

  • @svenomick5857
    @svenomick5857 Рік тому

    Very well explained Cheers Mick

  • @muhamadsyazwan19
    @muhamadsyazwan19 2 роки тому

    great video and great explanation, please do more!!

  • @FranciscoLeotteDoRego
    @FranciscoLeotteDoRego 3 роки тому

    Another brilliant video! Congrats

    • @StepstoPodium
      @StepstoPodium  3 роки тому

      Thank you so much Francisco! 😄💪💪

  • @attackfpv
    @attackfpv Рік тому

    Love the channel man thanks!

  • @FunTube4You
    @FunTube4You 2 роки тому +2

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

    • @StepstoPodium
      @StepstoPodium  2 роки тому +1

      Very low performance through the whole power band!

  • @BNAdv
    @BNAdv 3 роки тому +2

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

    • @StepstoPodium
      @StepstoPodium  3 роки тому

      Muito obrigado Zé! 😄 grande abraço 💪

  • @vladi_g
    @vladi_g 3 роки тому

    I did not know about such a mechanism. Interesting.

    • @StepstoPodium
      @StepstoPodium  3 роки тому +1

      The more you know...! #knowledgeispower 😁

  • @chris-has-problems
    @chris-has-problems Рік тому

    Another aweosme vid!!

    • @StepstoPodium
      @StepstoPodium  Рік тому

      And some new ones are coming out really soon!!

  • @topstar3
    @topstar3 3 роки тому

    Another wicked video my man!

    • @StepstoPodium
      @StepstoPodium  3 роки тому

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

  • @MaverickM1
    @MaverickM1 Рік тому +1

    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.

  • @lappieslabuschagne2428
    @lappieslabuschagne2428 Рік тому

    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
      @StepstoPodium  Рік тому +1

      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

  • @danielmendoza4386
    @danielmendoza4386 2 роки тому +1

    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!

  • @BasaysayTv
    @BasaysayTv 5 місяців тому

    Can u make a video on how air suction valve works? Or air intake system of motorcycle for euro 4 compliance

  • @miro_s
    @miro_s 10 місяців тому

    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
      @StepstoPodium  10 місяців тому +1

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

    • @miro_s
      @miro_s 10 місяців тому

      @@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
      @StepstoPodium  10 місяців тому +1

      @miro_s exactly!

  • @dduj777
    @dduj777 6 місяців тому

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

  • @g.g4816
    @g.g4816 2 роки тому

    Great video

  • @dirkventer8112
    @dirkventer8112 3 роки тому +1

    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
      @StepstoPodium  3 роки тому

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

    • @dirkventer8112
      @dirkventer8112 3 роки тому

      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
      @StepstoPodium  3 роки тому

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

    • @dirkventer8112
      @dirkventer8112 3 роки тому

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

    • @StepstoPodium
      @StepstoPodium  3 роки тому

      I sure will!! 🙌🙌🙌💪💪💪

  • @NirHason
    @NirHason 3 роки тому

    You're a genius! Thanks! 👌👌

  • @Dell_xD
    @Dell_xD 2 роки тому

    thank you!

  • @ironken1796
    @ironken1796 3 місяці тому

    I'm still not clear on how much effect the powervalve has on compression ratio and exhaust port timing.....does its action effectively raise and lower the exhaust port changing timing as well? Does the compression ratio change (higher compression at low rpm when the valve is closed, and vise versa when open?)

  • @MaterToys
    @MaterToys 2 роки тому

    Awesome vid thanks

  • @markbrynteson5141
    @markbrynteson5141 2 роки тому

    Thank you sir

  • @tristanschurz2878
    @tristanschurz2878 Рік тому

    Where can I buy the clip holding down the rod

  • @samik83
    @samik83 2 роки тому

    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.

  • @tonycerino1736
    @tonycerino1736 2 роки тому

    Cool channel. I subscribed

  • @rztrzt
    @rztrzt 3 роки тому

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

  • @2WheelDerness
    @2WheelDerness Рік тому

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

    • @StepstoPodium
      @StepstoPodium  Рік тому +1

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

  • @bikevault2302
    @bikevault2302 4 місяці тому

    if the power valve is restricted due to using the green spring screwed in, can this cause over heating?

    • @StepstoPodium
      @StepstoPodium  4 місяці тому

      That's a really good question. It can!

    • @bikevault2302
      @bikevault2302 4 місяці тому

      @@StepstoPodium thanks for the reply. When i started i put a green spring in with the pre-load screwed in too. Now I'm riding better my engine is running very hot and have hanging rev issues. Might be an air leak but i'm looking for other reasons too.

  • @swedish_sadhguru3854
    @swedish_sadhguru3854 11 місяців тому

    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?

  • @venkatravanappar5104
    @venkatravanappar5104 Рік тому

    How to set squares for Hero Hunda

  • @vijayam1
    @vijayam1 Рік тому

    Brilliant..

  • @DoerOfTheThinkers
    @DoerOfTheThinkers 2 роки тому

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

    • @StepstoPodium
      @StepstoPodium  2 роки тому +1

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

  • @ServeraServera0
    @ServeraServera0 Рік тому

    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

  • @billbright1755
    @billbright1755 Рік тому

    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
      @StepstoPodium  Рік тому +1

      😂😂😂😂😂 loved the comment 👌😄

    • @BrianDoherty-e8s
      @BrianDoherty-e8s Рік тому +1

      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!

  • @EarthSurferUSA
    @EarthSurferUSA Рік тому

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

    • @EarthSurferUSA
      @EarthSurferUSA Рік тому

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

    • @EarthSurferUSA
      @EarthSurferUSA Рік тому

      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.

  • @steveh545
    @steveh545 3 роки тому

    brilliant!

  • @gixxerlemans
    @gixxerlemans 3 роки тому +1

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

  • @ls1_cammeroh
    @ls1_cammeroh Рік тому

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

  • @coreyhanson5263
    @coreyhanson5263 3 роки тому +1

    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
      @StepstoPodium  3 роки тому +1

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

    • @rostifardian
      @rostifardian 2 роки тому +2

      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

  • @wolftracks2033
    @wolftracks2033 3 роки тому

    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
      @StepstoPodium  3 роки тому

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

    • @wolftracks2033
      @wolftracks2033 3 роки тому

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

  • @gregoryrogers6100
    @gregoryrogers6100 Рік тому

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

  • @AbhaySingh-zx8ff
    @AbhaySingh-zx8ff 6 місяців тому

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

  • @marksteinhorst5855
    @marksteinhorst5855 Рік тому

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

  • @stevennova6692
    @stevennova6692 2 роки тому

    What difference between power valve and reed valve

    • @rostifardian
      @rostifardian 2 роки тому

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

  • @user-nb3tc8kl5i
    @user-nb3tc8kl5i 3 місяці тому

    All good but you did mention only the mechanical valve and forgot to mention the electric power valves operated by a servo motor. There are many manufacturers using this, Yamaha included !

  • @Littlewormmm
    @Littlewormmm Рік тому

    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

  • @HeAdChEeSe1983
    @HeAdChEeSe1983 Рік тому

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

  • @JoaoSilva-gs5jb
    @JoaoSilva-gs5jb 3 роки тому

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

  • @guarapo66
    @guarapo66 8 місяців тому

    Like a Vtec , interesting

  • @ricardobh2979
    @ricardobh2979 3 роки тому

    Show ✌🏾

  • @jakespeed6515
    @jakespeed6515 Рік тому

    In Yamaha we Trust 🙏!

  • @deddyromadhon9840
    @deddyromadhon9840 3 роки тому

    you are like ibrahimovic

  • @tris8312
    @tris8312 3 роки тому

    Yamaha TZM-150 legendary YPVS

  • @ellgwapo.1754
    @ellgwapo.1754 Рік тому

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

  • @TheCraigy83
    @TheCraigy83 Рік тому

    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 .

  • @TheEnduroClub
    @TheEnduroClub 3 роки тому

    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?

  • @openidqd
    @openidqd 2 роки тому

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

    • @StepstoPodium
      @StepstoPodium  2 роки тому

      The size determines timing

    • @openidqd
      @openidqd 2 роки тому

      @@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
      @openidqd 2 роки тому

      @@StepstoPodium для будущих поколений оставлю объяснение от Yamaha технологии ypvs: ua-cam.com/video/4kERsqKC9Q4/v-deo.html

  • @bodyfitnessworkouts7210
    @bodyfitnessworkouts7210 3 роки тому

    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
      @StepstoPodium  3 роки тому

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

    • @bodyfitnessworkouts7210
      @bodyfitnessworkouts7210 3 роки тому

      @@StepstoPodium yz 125 1992