Learnt to ride on an RZ250. When the valves opened and you were in the powerband it felt so smooth like the pistons were coated with teflon, excellent engineering for its time
I am an old school mechanic that knows the power valve very well. The easiest way to explain the working of it and what it does is. When the motor runs at low RPM you want back pressure in exhaust to make more torque for a better launch. When throttle is wide open you want full exhaust flow to get RPM up fast ( power ). So the valve will close off flow lets say at 50% at idle causing back pressure. as the throttle opens the vales in the yamaha XL engine opens the valves as more throttle is applied so as you give it more gas the flow of exhaust opens up to let RPM climb. so more restriction at lower RPM gives the engine more torque and wide open throttle lets full flow for max power. They had this also on the FZR and R motorcycle models as there was a flap built into the exhaust to cause low RPM back pressure. so torque is needed at low RPM and power is needed at high RPM and that is what a power valve does.
Thats partially wrong. It dont causes exhaust backpressure, which is regulated over silencer inner diameter. The valve changes GAS EXCHANGE TIMING, which causes change in compression, and much more...
@@herrderkolbenringeyeah that's what the video was trying to explain it's still hard to understand fully though because they don't really explain much I'm assuming it's because these guys who made this video don't really speak English
This system like Vtec for 2 stroke engine...I have old Kawasaki with KIPS system, that more efficient than yamaha, because KIPS system are not electronic.
Thanks Yamaha. the older 2-stroke jetski's with this feature were beasts! My friend who has an expensive Seadoo is blown away by how much grunt my old '03' gp1200r ski has. You can hear the engine note change and feel the power increase as the valve profile adjusts to the higher RPM. Such a great engine when given the right adjustments, It loves the oil though ;) keep up the good work, yamaha 😊🥰👍
"Old tech now" ? Only because 2-strokes aren't prevelant today. The ones still around still use power valves.Yamahas YPVS, Hondas ATAC, Kawasaki KIPs and Suzukis whatever it was called.after
Depends on the type of the system. The one used by Yamaha (ehm, Zuki and practically all others) is the purely mechanical one - position of the valve opening depends purely on engine speed. Actuator typically called "governor" is driven by the primary drive - governor translates engine speed to displacement transmitted via various levers to the valve itself. Honda just before finishing its (dirty to mother earth) two stroke program introduced sort of more advanced system, where it was controled by electric servo - adding more informations to be considered for valve opening, such as throttle opening, gear shifted and maybe some others. Bright idea, but practically it was cable wire driven and not entirely robust system to work flawless. If you are asking what the valve itself is doing inside "the engine", that is a separate story. Practically what do you want is to maximaze the time the pressure is being applied to the piston, hence to let gas expanding as long as possible increasing the engine torque, hence power at given speed. This generally improves the effeciency of rec. piston engine. Of course because it is a 2T technology, your expansion time is limited by opening the exhaust port from which it expands to exhaust - piston driving drops rapidly, it's timing is practically set by the upper edge of the exhaust port - being what is effectively changed by the valve itself. Valve is variable exhaust port top edge. As the engine is running slow, you have more time for everything, hence you can move the edge of the exhaust port down (valve goes down and closer to piston) - hence improving efficiency of the "working stroke". But as you speed goes up, the overall timing of all events is completely different and your "low positioned edge" of the exhaust port starts being exactly counter productive. Engine something like "stalls" in terms of power and you need to make you exhaust port edge higher so as exhaust dynamics can work well with respect to high engine rpm. Consequently valve goes up (and far from piston) effectively opening the exhaust port sooner. It's a pure trade off. Exactly the same situation like spark advance timing. This system has a direct counter part in 4T technology - exhaust camshaft phaser. Phaser also adjust the time when exhaust valve starts to open (effectively the time when the expansion curve is affected by the loss of gas exiting the exhaust port).
@@marekriha8992👍 , he might mean for the likes of a DTR not a YZ , if it’s a Yz then he’s better ask a factory mechanic how to gain that fraction more power ( they know best and will tell you by experience ) . As for the DT”R” then it’s well tuneable like grinding out the power valve from 10%-30% in some parts . You will have no bottom end power till 7 k ( it’s stupidly underpowered and you burn out clutches faster ) and then it comes in well more aggressive given you matched the exhaust to the exact tuned set up . At best you can turn a DTR into a supermoto ( lower to the ground and done right your going to achieve 105 -115 mph ) . But the low stoop on the front end you defo need a front fender brace before you learn that plastic mud guard try’s to fold down going into the front wheel . A good concept of the band tuning is like what you said about Honda , especially with the difference of the track NSR and the CR . Ones built for less aggressive band but longevity at high revs and the CR comes in more aggressive and pinned to long goes bang lol .
not really.. guillotine power valve/blades are common on rotax, suzuki, ducati/cagiva, Minarelli and many engines since the 90's. Yamaha stopped making the cylindrical "cotton reel" design running across the top of the exhaust port using the servo motors in the late 80's and all the Tz's from 90's onwards have a guillotine-based system.
GREAT DESIGN ...THE RPM AT 6000 THE YPVS START FUNCTION ...TO SUPPLY HOT AIR BECOME SOO POWERFULL COMPRESSION AT THE BURNING SYSTEM...EXCELLENT ...! TRY BEFORE ...??? TZM 147 CC CAN MAKE YOU FLY ...!🎉OLD YET STILL VERY ACTIVE *# HONDA CBR 250CC TOP SPEED 199 KMPH , TZM 147 CC TOP SOEED 240 KMPH ...***
Yamaha patented the power valve in 1977 & all the Japanese manufacturers had their own versions - Kawasaki's KIPS, Honda's ATAC, Suzuki's AETC, so the list is endless.
@@mrsilbo6499 YPVS, RC VALVE, AETC has same model they use Bridgeport different with Kawasaki KIPS they use 2 small port in the side of exhaust port or actually it's called power valve but in KX125 it's combine Bridgeport with KIPS. Sorry for bad english
Eagerly waiting for the the all-new 2022/23 R1 with a totally new engine & looks, have any news about it if so please share it, what's happening with Yamaha now the legendary Japanese company who is famous for her performance -oriented most eye catching state of the art products r doing so disappointing in the designing prospectives (specially in the hyper naked & Sbk segments, scooters and Maxi scooter segment r doing excellent) come on Yamaha just wake up and do something new & futuristic, please don't repeat the same boring retro type design portfolio(total R-series) again and again year after year it's enough give us a break. Please don't disappoint this time. Because ❤️"Yamaha is Yamaha always the best" ❤️
I had a 3ma and at one point the valves came loose and went into the combustion chamber. What a mess. Lucky for me I was riding slow and it did minor damage but it was a good excuse for some upgrades if you know what I mean 58bhp later and then the bike got stolen. 😢🤯🤬
The yamaha power valve system ( YPVS ) is realy intallegent idea that gives the cylinder room fresh air and it explose more oxygen efffiency and I know that Yamaha has an İnternational Licenced of this system .
Learnt to ride on an RZ250. When the valves opened and you were in the powerband it felt so smooth like the pistons were coated with teflon, excellent engineering for its time
I am an old school mechanic that knows the power valve very well. The easiest way to explain the working of it and what it does is. When the motor runs at low RPM you want back pressure in exhaust to make more torque for a better launch. When throttle is wide open you want full exhaust flow to get RPM up fast ( power ). So the valve will close off flow lets say at 50% at idle causing back pressure. as the throttle opens the vales in the yamaha XL engine opens the valves as more throttle is applied so as you give it more gas the flow of exhaust opens up to let RPM climb. so more restriction at lower RPM gives the engine more torque and wide open throttle lets full flow for max power. They had this also on the FZR and R motorcycle models as there was a flap built into the exhaust to cause low RPM back pressure. so torque is needed at low RPM and power is needed at high RPM and that is what a power valve does.
does it also create better fuel consumption than an engine without power valve?
Thats partially wrong. It dont causes exhaust backpressure, which is regulated over silencer inner diameter. The valve changes GAS EXCHANGE TIMING, which causes change in compression, and much more...
@@herrderkolbenringeyeah that's what the video was trying to explain it's still hard to understand fully though because they don't really explain much I'm assuming it's because these guys who made this video don't really speak English
@@herrderkolbenringe Es geht darum die Strömungsgeschwindigkeit zu optimieren richtig? Ähnlich wie wenn ich einen zu klein/großen vergaser fahre würde
This system like Vtec for 2 stroke engine...I have old Kawasaki with KIPS system, that more efficient than yamaha, because KIPS system are not electronic.
Thanks. I completely misunderstood how this works. Nice to know the facts !
Fantastic yamaha
Super extraordinary guys move on next step
Thanks Yamaha. the older 2-stroke jetski's with this feature were beasts! My friend who has an expensive Seadoo is blown away by how much grunt my old '03' gp1200r ski has.
You can hear the engine note change and feel the power increase as the valve profile adjusts to the higher RPM. Such a great engine when given the right adjustments, It loves the oil though ;)
keep up the good work, yamaha 😊🥰👍
Tu yang sekali open mencanak boss pergi..fuhh padu
Full of love
Old tech now, but very clever when introduced.
"Old tech now" ?
Only because 2-strokes aren't prevelant today. The ones still around still use power valves.Yamahas YPVS, Hondas ATAC, Kawasaki KIPs and Suzukis whatever it was called.after
@@holdernewtshesrearin5471 I meant old as in invented a long time ago, certainly not old as in obsolete! 😉
@@mrsilbo6499 - gotcha.
perhaps we should introduce a powervalve on the intake side as well, now that 2 strokes are seeing a revival with fuel injection.
@@holdernewtshesrearin5471 ktm have much better now and i don´t mean thats electric but shape and direction how it is opening
Wow. This is perfectly brilliant and amazing!
nice video (y)
Melhor não tem no mundo
Got it in my rd 350...😊
このビデオには問題があります。 全世界が慣れ親しんでいるYPVSは、この新しいギロチンシステムではなく、回転軸で構成されています。 最近の世代に不信感を与える可能性があるため、担当部門は古いバージョンも表示する必要があります。 現在のギロチンシステムには別の名前が付けられるかもしれない。
Ypvs ❤
Crazy
Yess..we are kando
Basically to solve the low end torque loss in two strokes, something similar like EXUP. Brilliant..
Bring back 2strokes
Is HPDI technology similar to this.
Sir i have two stroke cylinder i want to increase its rpm power please help me how i can increase the speed from its ports. Please help me tell me sir
Can we set this setting in our yamaha 2 stroke bike . How the valve actually works ? It works on combustion in the piston or in which it works ?
Depends on the type of the system. The one used by Yamaha (ehm, Zuki and practically all others) is the purely mechanical one - position of the valve opening depends purely on engine speed. Actuator typically called "governor" is driven by the primary drive - governor translates engine speed to displacement transmitted via various levers to the valve itself. Honda just before finishing its (dirty to mother earth) two stroke program introduced sort of more advanced system, where it was controled by electric servo - adding more informations to be considered for valve opening, such as throttle opening, gear shifted and maybe some others. Bright idea, but practically it was cable wire driven and not entirely robust system to work flawless.
If you are asking what the valve itself is doing inside "the engine", that is a separate story. Practically what do you want is to maximaze the time the pressure is being applied to the piston, hence to let gas expanding as long as possible increasing the engine torque, hence power at given speed. This generally improves the effeciency of rec. piston engine. Of course because it is a 2T technology, your expansion time is limited by opening the exhaust port from which it expands to exhaust - piston driving drops rapidly, it's timing is practically set by the upper edge of the exhaust port - being what is effectively changed by the valve itself. Valve is variable exhaust port top edge. As the engine is running slow, you have more time for everything, hence you can move the edge of the exhaust port down (valve goes down and closer to piston) - hence improving efficiency of the "working stroke". But as you speed goes up, the overall timing of all events is completely different and your "low positioned edge" of the exhaust port starts being exactly counter productive. Engine something like "stalls" in terms of power and you need to make you exhaust port edge higher so as exhaust dynamics can work well with respect to high engine rpm. Consequently valve goes up (and far from piston) effectively opening the exhaust port sooner. It's a pure trade off. Exactly the same situation like spark advance timing.
This system has a direct counter part in 4T technology - exhaust camshaft phaser. Phaser also adjust the time when exhaust valve starts to open (effectively the time when the expansion curve is affected by the loss of gas exiting the exhaust port).
@@marekriha8992👍 , he might mean for the likes of a DTR not a YZ , if it’s a Yz then he’s better ask a factory mechanic how to gain that fraction more power ( they know best and will tell you by experience ) . As for the DT”R” then it’s well tuneable like grinding out the power valve from 10%-30% in some parts . You will have no bottom end power till 7 k ( it’s stupidly underpowered and you burn out clutches faster ) and then it comes in well more aggressive given you matched the exhaust to the exact tuned set up . At best you can turn a DTR into a supermoto ( lower to the ground and done right your going to achieve 105 -115 mph ) . But the low stoop on the front end you defo need a front fender brace before you learn that plastic mud guard try’s to fold down going into the front wheel . A good concept of the band tuning is like what you said about Honda , especially with the difference of the track NSR and the CR . Ones built for less aggressive band but longevity at high revs and the CR comes in more aggressive and pinned to long goes bang lol .
I need dt200 piston sleeve kit please
plz launch xsr155 waiting since frm 2 years plzzz☹🙏😓
Looks like a honda RC valve.
2 stroke is the most powerful engine ever....hope it more better 2 stroke engine in future r&d.... really miss 2 stroke motorcycle....prenggggggf!!!!!
it like RC valve in honda
Guys what gona hapend if I leave open power valve on 80% ?
I preferred my ordinary 350LC to my YPVS.
It's has different device than actual YPVS in older 2 stroke yamaha engine, YPVS nowadays same like AETC suzuki had.
not really.. guillotine power valve/blades are common on rotax, suzuki, ducati/cagiva, Minarelli and many engines since the 90's. Yamaha stopped making the cylindrical "cotton reel" design running across the top of the exhaust port using the servo motors in the late 80's and all the Tz's from 90's onwards have a guillotine-based system.
@@mohba01 what are the advantages of guillotin type?
GREAT DESIGN ...THE RPM AT 6000 THE YPVS START FUNCTION ...TO SUPPLY HOT AIR BECOME SOO POWERFULL COMPRESSION AT THE BURNING SYSTEM...EXCELLENT ...! TRY BEFORE ...??? TZM 147 CC CAN MAKE YOU FLY ...!🎉OLD YET STILL VERY ACTIVE *# HONDA CBR 250CC TOP SPEED 199 KMPH , TZM 147 CC TOP SOEED 240 KMPH ...***
I have a 1989 Yamaha DT 125lc YPVS
yamaha should have the 2 strokes mastered by now.they been making them forever.if they dont by now.they never will.
Miss the 2 - stroke smell. I open the car window when a moped is in front. What engine exept the RD 350 had or has it?
Yamaha patented the power valve in 1977 & all the Japanese manufacturers had their own versions - Kawasaki's KIPS, Honda's ATAC, Suzuki's AETC, so the list is endless.
@@mrsilbo6499 YPVS, RC VALVE, AETC has same model they use Bridgeport different with Kawasaki KIPS they use 2 small port in the side of exhaust port or actually it's called power valve but in KX125 it's combine Bridgeport with KIPS.
Sorry for bad english
@@Alvon_PR It has to be different to the YPVS setup, otherwise there would be patent infringement! Thank you for sharing the details. 👍
@@mrsilbo6499 my favourite weird name is from rotax - The RAVE (Rotax Adjustable Variable Exhaust) todays kids can relate to this .. hahaha
@@mohba01 Brilliant! 😄
Eagerly waiting for the the all-new 2022/23 R1 with a totally new engine & looks, have any news about it if so please share it, what's happening with Yamaha now the legendary Japanese company who is famous for her performance -oriented most eye catching state of the art products r doing so disappointing in the designing prospectives (specially in the hyper naked & Sbk segments, scooters and Maxi scooter segment r doing excellent) come on Yamaha just wake up and do something new & futuristic, please don't repeat the same boring retro type design portfolio(total R-series) again and again year after year it's enough give us a break. Please don't disappoint this time. Because ❤️"Yamaha is Yamaha always the best" ❤️
I had a 3ma and at one point the valves came loose and went into the combustion chamber. What a mess. Lucky for me I was riding slow and it did minor damage but it was a good excuse for some upgrades if you know what I mean 58bhp later and then the bike got stolen. 😢🤯🤬
New 2023 snowmobile?
I have 🇯🇵Rz 125 ypvs ❤🇱🇰
Superkips, RC Valve
Basically a powervalve from the 80's
Imagine ditching electronically operated power valves in the days of modernised 2 strokes...
XSR155 India Launch, we are waiting.......
Bhul ja beta...kis jamane mein rhe rahe ho. Yamaha ne kardi launch Fz-X as Xsr . Try it out it's good as beginner bike.
Podrían traducirlo a español
R15M now in India 💥
Bring this to snowmobile 600 twin and 850 triple for 2025
The yamaha power valve system ( YPVS ) is realy intallegent idea that gives the cylinder room fresh air and it explose more oxygen efffiency and I know that Yamaha has an İnternational Licenced of this system .
Prefer to hear somone talking/explaining
That valve has destroyed more engines than anything else.
The music is annoying. Some verbal explanation would have helped.
ASBACH
That power curve is a lie.
1. It be YSP! Not YAMAHA = Our Royal - Orient name! You be, a fraud - on our radar!