Secondary Throttle Valve Mod - should you do it?

In this video I talkk about removing your secondary throttle bodies and is it a good idea. I also talk about how they work.
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[@OldManTony]

Being an ex SV1000 owner, I was always arguing this with other owners, but they read about it on the forum, so it must be true!

[@ipwn951]

I made a comment on your speed porting video about having a retractable restriction at low revs (having no idea that secondary throttles were a thing) . Another addition to my list of inventions that someone else thought of probably 30 years ago 😂

[@stevemasterson7776]

Yeah it's not a bad mod on track bikes with experienced riders. The secondary is only there to stop the rider from being too ham fisted w the throttle. The fact is the 2nd butterfly is a massive restriction to the airway that is unnecessary if the rider is smooth on the throttle.

[@akupehsluarketatAR]

agreed.

[@markariewilliams]

Good explenation thanks, just removed mine from my gtr1400 and added fuel controller and now is as smooth as it was stock but way more torque from 1500rpm to redline as opposed to stock, 6000rpm when the flies open, different bikes i suppose...

[@DANTHETUBEMAN]

I removed all the butterfly 🦋 valves primary secondary and throttle! I just use the clutch and the gears now!!!

[@justinhensley1384]

Buddy christ!!!! That's awesome. Almost made the mistake of taking them off my 06 750. Thanks for explaining how they work.

[@Nathan-kw2hs]

i keep seeing how the bandit is smoother at low revs and has more top end with this mod. Haven't done it yet since i couldn't make sense of it, thanks for the vid :D

[@Yamaprilia]

I removed mine on a 05 zx10r. I removed the shaft too so i didnt just remove the plates like most do. It was then mapped to suit and I must say it ran 100% spot on and made really good peak power. It may have lost a small amount lower down but I didnt notice it and it ran smooth and clean from low rpm. Not sure all bikes would though, especially big v twins.

[@Krazi_Kawi]

Glad I saw this because I was watching this video before testing on my 05 zx10r😂

[@tmannpd7290]

I was mislead years ago and thought it improved throttle response etc. I was educated that the 2nd fly was to control big power bikes from wheelies in low gears when throttling down. Thank you for the better education. 2013 Zx14 ABS

[@Zx14rrrrrrrrrrr]

Some people want to wheelie lol

[@Popsm0ke]

..... haha , If you need training wheels you should not be on a big bike

[@tmannpd7290]

@@Popsm0ke yea no joke. Bike ran cleaner without it.

[@killfase01]

So pull it out before dyno tuning. Got it 👌

[@cliffw1210]

Thanks for this explanation. I’m currently building a track gxsr and am new to secondary throttle body (usually a 4 wheel vehicle and aircraft mechanic, and was confused at why the “top” butterfly valve wouldn’t move with a twist of the cables. I figured it was computer controlled but wasn’t sure and my Haynes didn’t have an explanation of it so KZbin I went. Thanks from across the pond.

[@YAMR1M]

An old video.. But still worth a comment... So I will admit I am one of those nob heads who has done this.. BUT let me explain. Why it was a good idea and why it is like you said a very BAD idea too... OK my case was this..... The bike was a GSXR600. The throttle bodies were swapped for GSXR750 ones which are larger. The bike was running Suzuki official Yoshimura race kit supersport 600 spec cams. Thinner supersport legal head gasket and a full titanium exhaust with no exhaust valve. It was built for a purpose even though it was a road legal bike and it was used to successfully break the Nürburgring lap record. We needed to have instant throttle response and in first and second the ECU would not allow the secondaries to open 100% to make the bike more tractable and nicer to ride. So it was much more focussed and could be compared to cutting steak with a scalpel not a butter knife. It served a purpose. Now the bad.. Starting from cold. The secondaries act like a choke. it richens up the mixture and if you ride the bike cold it slows down the secondaries opening and keeps the mixture rich until it gets out of that choke phase of the ECU program. Remove them and the bike doesn't know what to do if you snap open the throttle as the bike still thinks the secondaries are still fitted and then the bike does very lean, bogs and then chimes back in again and is not only horrible to ride but dangerous. In the wet the instant response is too direct for most riders as any bike with over 100bhp needs to be treated with respect so that slightly slower opening secondary helps make the bike feel linear and not as brutal as it could be in the wet too. It all does a very good job so we don't even realise how well it is doing. 99% of riders who have ridden bikes with carbs have used CV carbs and those do a similar thing. The secondary butterflies mimic the CV carb slide. If anyone has ridden with flat slide carbs or older carbs will know on a 4 stroke they have to fit "Pumper" carbs on bigger engines that have a small mechanical pump that works like a fuel filled water pistol and squirts neat fuel into the inlets to try and stop that instantaneous lean spot and the bogging you get at times. Removing the secondaries is like now using flat slide carbs with no pumper. But if you have very good throttle control it can work as well as having the secondaries fitted and make the bike more responsive. But the downsides are greater than the benefits for road use by 10:1. If you use the bike on track then it can make a difference, but for day to day use it makes the bike so much worse. Would I do it again?? Yes in a heartbeat... But only if I have a reason to do it... Would I do it on a road bike? No... The only bike I know this was a genuine performance enhancement was the Kawasaki ZZR1400 which will never give 100% throttle in the lower gears and if someone wants to use it for some drag racing and bragging rights it does make the bike accelerate quicker (NOT faster) but you still have to live with the problems it causes on the road.

[@dirtygarageguy]

Love you yes, no comment

[@daniyk5746]

I am ZX14 owner, Please i would like to know what kind of problem will it creat at road use ?

[@sonicgauge1]

I removed them on my 07 zx14 after installing a power commander and I'm so glad I did, power used to come on at 5000 rpm, now it comes on at 3000 = a mAjor improvment to say the least. (I did ride it around for about a month with the commander before removing secondarys, and was advised not to remove them unless I had the power commander)

[@dirtygarageguy]

I changed a power command and the STV's and now my power comes on earlier.......hmmmm therefore STV! LOL what the fuck? Maybe it was the power commander???

[@Popsm0ke]

Best mod you can do on a gen1 zx14

[@sonicgauge1]

@@dirtygarageguy , lil late but, power comander was first I rode it for little while (power band started at 5k same as stock) n then took the secondary flys out (which let it start at 3k).. From what I understand they retard the timing in 1st and 2nd gear and have the secondary flys open slowly when you give a lot of throttle quickly so people don't hurt themselves.. Oh and the flys out made a better diference than the power comander did. So wtf your self eh.. To be fair I have heard that on gsxr's taking the flys out fucks up the way they run but on first gen zx14's it's most recommended thing to do , free hp..

[@MajorArchitect-0]

I'm adding ninja ex650 throttlebady to an old 82 Yamaha vision for an EFI conversion. This definitely helps me understand the system better. probably gonna be tricky to tune :P

[@nobbytrussin]

Only just seen this. I've been rattling on about this for ages - the trusty CV carb did essentially the same thing with the vacuum operated slide but the conspiracy theorists think it was all about emissions. In fact yamaha did a hybrid on their early injection systems with a vacuum operated slide but injection intake body.

[@fluffycat087]

The primary butterfly is already doing what the slide did be it CV or a a cable operated flat slide. At partial positions it is restricting intake flow and creating higher velocities having a secondary valve might only be to smooth throttle inputs. At low rpm and low speeds the ECU will probably run the motor lean and has the secondaries less open to reduce emissions to pass EU requirements they will also help damp airbox sound levels for the drive by requirements.

[@bobbob8387]

Love the sound of rain! Makes the video lot more cosy.

[@remroo]

Well had a Gipro ATRE on my ZZR1400 that choose the most unrestricted gear mapping. It does only setting the secundairy throttles more open like they do in that 6th gear. The difference was absolutely bizar and also have the difference on dyno chart: +21nm 11hp at 2500tpm spread over that low end and keeping up a few nm and hp the hole rev range in 3rd gear! The difference feeling in first and second gear was even bigger. It was even much much smoother and predictible. So the story has two sides, indeed removing it will be not a good idea but with many high performace bikes they used it more to restrict your immense powerhouse than optimize it.

[@dirtygarageguy]

"So the story has two sides, indeed removing it will be not a good idea but with many high performace bikes they used it more to restrict your immense powerhouse than optimize it." - I've heard this quite a lot from a few different sources. Yes the STV starts to close at the top end, but I think this explaination is wrong. Lets just say your bike produces 175HP at the wheel with the STVs closing at max rpm and 188HP with it re-programmed. People say this is to restrict the bike, which is as funny as fuck - like 175HP is restricted? In road terms that like going 190mph and 198mph, because 190mph is safe and 198mph isn't? I don't know what the reason is why this kicks in and I'm going to contact Suzuki and find out why. But if I had to guess it could be for a few reasons. 1) Some bikes are restricted by top speed - legal reasons depending on country etc. 2) Hitting the rev limiter when at high load (going top speed) is harsh on the crankshaft and cause torsional vibrations that can throw rods and break cranks. So to prevent this the engine can lower the torque just before this limit is reached so when it does reach the rev limiter - the stress is reduced. 3) Some other reason that I can't think of. I'll do a video on this soon. But I can say its probably (with like 95% certainty) NOT the following. 1) A restriction of power. 2) Emissions reasons 3) To stop you having fun, the engine produces silly power, that last little bit isn't making that much difference.

[@remroo]

By calling me a dickhead I want to say goodbye... I don’t get this hostility, that is not my intention anyway. Have a nice day✌️

[@dirtygarageguy]

Oh you poor darling - bye

[@lillnemo1]

@@remroo you know what ATRE means? Advanced TIMING RETARDING eliminator. It makes your bike think its in 5th (sometimes 6th) gear to remove timing retarding in first, second and sometimes 3rd gear. Its about TIMING... IGNITION... SPARK... you gain most hp cause of earlier spark, not cause of STV opening a bit sooner

[@Popsm0ke]

@@lillnemo1 .....you idiot , all the tre does is trick your bike to open the secondary butterflies faster. Brock Davidson exposed Ivan. Putting a resistor in a black box and lied about what it really does. I don't get why you people pay for a damn box when all you need is a number 2 phillips screw driver

[@benchandler6217]

So is that kinda the idea behind the early Yamaha exup valves in a completely separate way of coarse Love yr vids Matt they are awsome! My viewing is all over the place as you have so much I need to watch! The golden missing links! With no bullshit or PC keep up the good work fella

[@steve23464]

On my 05 zx10r there is a sensor that controls the stepper motor which in turn controls the 2nd throttle valve. I mistakenly removed this sensor so I could remove my valve cover. I say mistakenly because 1, I didn't have to remove it to gain access to the cover and 2 your not suppose to remove it. Once removed you have to take it to a dealer ($$) to get it synced again. If you don't get it re-synced then the 2nd valve no longer opens at all restricting rpm to about 5k. Solution for me was removing the butterflies. I honestly don't feel any power loss with them removed. Bit of electrician tape over the F1 light and done. But I get what your saying.

[@dirtygarageguy]

"Once removed you have to take it to a dealer ($$) to get it synced again." - It doesn't. There's a procedure to follow, that's all.

[@Popsm0ke]

Man go to Brocks Performance website there's plenty information and dyno charts. Or just type in zx14 diary it goes in to massive detail on removing the flies compared to Ivan's tre. The tre puts the engine in a very lean condition

[@mcfast52]

That is like the Go-kart guys with their 2T removing the power valve and thinking it makes their karts faster!

[@markdyson4704]

Yep. Some idiot removed the butterfly’s on my recently purchased GSXR. It works fine until operating temperature is reached, then it dies at low RPM and only is happy at 4K or above. It’s lovely in stop and go traffic. I’m having to purchase and install the secondaries now. FML

[@Dane.Reynolds]

Saw an STVE on eBay, had no idea what it was, thanks for explaining.

[@Zx14rrrrrrrrrrr]

Sure if you're trying to have a smoother ride leave them in but.. If you're trying to come off the line a little faster. Take them off and give that a feel

[@dirtygarageguy]

Off the line? Fuck off.

[@Zx14rrrrrrrrrrr]

@@dirtygarageguy lol take off. I had a 14. I tried this and it was more aggressive on take off. I did it just to try it. I didn't leave like that because I'm not that type of rider. But for some people it works.

[@shivamsamaroo2482]

Its called continuous velocity and can work under a vacuum system in the form of flat slides as well

[@dirtygarageguy]

Are you telling me something I don't know?

[@shivamsamaroo2482]

The Workshop im saying something i didnt see mentioned and is on the 2002 5pw and ik guys that do the cv slide delete ‘mod’ didnt know you would be my only audience ..so are you the only one can see the comments on the vid? Cause i would delete it you already knew lmao nah i really wont

[@donwolfjr1]

Well, this answers my question!! Thanks for the video!!!

[@PlebMotovlog]

People will believe anything if you promise them better performance. Shit, I could probably convince a decent amount of people to take a dump into their oil saying it will make it more slippery and cause less wear. But it has to be premium shit produced by us and sold at £50 per portion.

[@crackedemerald4930]

Pleb Motovlog turd oil: that's some great shit

[@Dpo2203]

Well I’ve fitted slightly smaller secondary’s and on the Dyno it gave 10bhp more at 2’500 rpm low down torque and power , I will add the bike has had a custom map 147bhp at the wheel and no snatchy Yamaha throttle . Pity they couldn’t get rid of the snatch with all their knowledge !

[@markvernon1218]

Removing those butterflies gets rid of the Suzuki hesitation issue, And litre bikes have plenty of torque anyway. Just my 2 penneth.

[@disekjoumoer]

I fucking lost it at "so Donald Trump's hairpiece doesn't grow legs and fuck off"😂😂😂

[@BJK1987AU]

Removed the secondary butterflys on my Kawasaki W800 since the computer control is all over the place for it due to the crap throttle body design. But ive also removed the airbox for pods and got a tuner on it now. I think removing them isnt for every bike. But it suited mine.

[@dirtygarageguy]

If you mess around with everything else OR you're tuning for racing and running it on a dyno then yes. But people are just removing them for the road. - great comment - matt

[@BJK1987AU]

I have done full exhaust, pod filters, o2 removal and tuner. Blocked the exhaust air injection and road tuned using a wideband O2 sensor. Its not a performance machine as its a retro bike turned cafe racer. Makes 55hp at the wheel on dyno and really strong flat torque curve.

[@mikegrady4]

BJK1987AU, 800cc and 55 hp?

[@BJK1987AU]

773cc. Its not made for speed. Its a very basic, understressed engine. doesnt rev high, SOHC, air cooled, no oil cooler. With crap brakes it doesnt need any more power.

[@mikegrady4]

Josh Rothwell, I still don't get all the talk about American V8s not having any power. They are designed to have great torque while still running on 87 octane fuel and last over 200k miles. Most are in trucks or large SUVs. If you have one that has to run on 91 octane, they make a respectable 500+ hp, some over 650 hp, others over 700 and still have the ability to run over 200k miles. These engine don't go in 450 to 600 lb bikes. They go in 6000 lb to 7500 lb vehicles and that changes everything. Displacement is the easiest way to make torque and you can shut down cylinders for fuel economy....but you are still pushing a brick.

[@MafiZed]

You deserve more sub's! great explanations and bluntness

[@rowlandstraylight]

Annoyingly, to the arss-dyno, the lumpy power delivery feels like more power because the rider feels it kick in harder. Most of the felt effect of 'performance ' exhaust I have appears to be rapid transition between reduced midrange performance and very slightly improved peak power. Feels naughty, but not ultimately as quick in road riding situations

[@shawnlibby675]

If you're trying to pour butterflies in a newer EFI sled you need to adjust with an ohm reader the throttle position sensor you also would need a wideband O2 sensor and some kind of computer to read the ECU on the snowmobile it has been done on some snowmobiles and bikes bought with tuning equipment but you've got to have something that can read the ECU on the sled

[@Benzz90]

Great explanation :) - I accidentally adjusted the sensor on the side when trying to get to my TPS for a throttle issue... How do you look to get this back to the "sweet" spot?

[@dirtygarageguy]

Get the service manual, there's a procedure you need to follow

[@mikegrady4]

Buell had the same deal....but on the exhaust side.

[@KIRBZVIDS]

Your contact is brilliant 😂

[@vmontalvo5591]

Removed sec flies on a 2007 ZX14r... day & night difference (in a good way :D) on lower RPMs. But starting to see increased engine temperature. Could it be caused by the flies out?

[@zensempai7371]

My guess would be a lean running condition with the extra air , no idea how much the FI adjusts mixture with these mods.

[@shawnlibby675]

You need to figure out how to run a wideband O2 sensor and get an AFr reading out of the exhaust.. I've also seen people make the throttle position sensor adjustable a little bit by modifying the screw holes my hair bigger to give the throttle position sensor some adjustment by hand read it with an ohm reader but look up on KZbin how to install a wideband O2 sensor in your exhaust of your snowmobile to read your air fuel ratios

[@Popsm0ke]

Removed from 2006 zx14 and it is a must you just have to add more fuel to prevent low rpm lean condition. I was ready to get rid of the motorcycle because it was so damn weak in the first 3 gears. I do want to remove the secondary shaft because it causes turbulence at high rpm

[@stefanlind79]

Enjoy your vids, and I respect your opinion about this matter. However, my V strom 1k K5 runs much better in the high range, making it more relighable during passes, because It responses much better when at highway speeds. As I understand, my ECU is programed to my bike to choke the engine in top end of 5th and 6th gear to keep the fairings to lift the bike into orbit in speeds past 200 km/h, making the top two gears more of overdrives than anything. The forums tell me to pull teeth of the sprockets to make it stronger but I really don't have to after removing the secondary flaps. I got an F1 code after a filter change and found that the actuator is not working prop. Most likely because I screwed around with the linkage and put the assembly out of alignment. My Strom is super twitchy in low gears now and I absolutely see the potential danger if theres no ECU-controlled LAG in low speeds if for some reason my hand would snap the throttle sending the bike of like a rocket. But I prefer my bike to response to My command rather than the ECU closing the secondaries during a truck-pass at highway speed. And Im getting used to take care in the low gears. If the system would not have failed I would prob never have thaught about removing them. If my bike where a gixxer with 180 hp for roaduse I would never have messed around with the plates except for maintenance, making them work as they where intended. Seems there are as many opinions about this, as are riders :) Cheers

[@PurpleMonstaHellcat]

stefanlind79 so overall you removed your second butterflies?

[@stefanlind79]

@@PurpleMonstaHellcat my strom had a secondary failiure, which made it real slow in top end/ gear, making it dangerous in passes etc. I dont recommend to take them off your bike. Regardless if the mecanics in the sec work or not, they need maintenance to stop from binding and acting up. I just choose to remove mine. Simple, stupid and happy

[@PurpleMonstaHellcat]

stefanlind79 yeah mine aren’t synchronized so I’m planning on removing them so I don’t had be to deal with low power. My bike won’t go past 60mph. Something about the tps.

[@stefanlind79]

@@PurpleMonstaHellcat maybe check funktion before you remove them, to exclude any other matter. The funny thing is though, I read about riders connecting PC, Boosters and deleters just to get around a software that control these flaps... the removal is free of charge an of course free of personal choice. I ve spent my money on s clutch-job to get rid of the rattle and shutter. Cheers

[@PurpleMonstaHellcat]

stefanlind79 I’ll let you know how it turns out

[@Soupy_loopy]

I was just kidding Matt. I've been sick all summer, not riding, so nothing better to do than troll KZbin.

[@porkchopspapi5757]

So as an automotive engineer, are you saying with a ecu reflash, which most will do, you should not remove the secondaries?

[@markpoxton1119]

B1250, left mine in, I reckon removing them who benefit racing high rpm, but ruin lower rpm drivability... And I spend 95% at lower midrange ;)

[@AuMechanic]

If you open the primary throttle plate by hand at the same rate the PCM control opens the secondary throttle plate, meaning both open together at the same rate, what difference will there be to having only a single throttle plate opening at the same rate with no second plate at all.

[@dirtygarageguy]

What that a question at the end? I'm a bit unsure......

[@AuMechanic]

Sort of, both plates opening at the same rate would be unity, or no pressure differential between them since they are opening at the same angle and rate and occupy the same throat area, and only a difference between the angle of each plate would represent any differential in pressure from one to the other. So if it is only when the rate and angle both plates differ we would need to know exactly how the PCM operates the secondary plate and when to know what it truly does and when. Does it simply limit the secondary rate to follow engine speed, similar to a CV carb to maintain a more constant velocity, or does it operate under other conditions too that has some additional effect. Knowing that you could predict exactly what would happen if you removed it. Example does the seconday open to follow RPM curve or MAP or both.

[@dirtygarageguy]

Similat to a CV, it's also like a traction control system for your ports, but pre-programmed. It is given the demand signal from the throttle position sensor and then opens the secondary to try to keep port velocities constant and in line with engine speed. People compalin that they don't work, and this is generally because they're throttle bodies need synchronising and their TPS is out of alignment. As for the 'other' conditions yes, but depending usually on the bike. The higher end newer bikes have ECU that try to measure/calculate dynamic loads and power at the output-shaft. With this information they can 'actively-tune' as they operate to a degree.

[@AuMechanic]

Sounds like it use MAP / RPM for speed density it uses for injection timing it can calculate load over RPM from. But perhaps the curve of it follows other conditions. Hooking up a scope to MAP, RPM, and both TB angles would reveal what it really does and wouldn't have to rely in the manufacturers claims on the back of the box about what it does, that I am always skeptical of. Having a separate metering plate above the main throttle plate is as old as carbs and used to follow velocity drop, but EFI isn't a carb and does not need to do that, which leaves the question we why else do it. I don't think the fat lady has sung on this one yet till there is more detail on it to say definitively if its as good as they claim and why or its just for pong control at a small expense of performance.

[@lillnemo1]

You clearly misunderstood. The secondaries DONT necessarilly follow frimaries on the same rate!!!

[@victorgonza4528]

increase port velocity while reducing volume , got it .

[@matty2361]

So on some of the gsxrs. On wide open throttle at high rpms the stv isn't open 100% around 90%. Programs like woolich tuning you can change the percentages making it 100% open on full throttle giving it a bit more power. Obviously it needs to be on a dyno when doing this but would you recommend getting them re programmed?

[@dodge4210]

Great information and fkn vocabulary. Keep it up bud. 👍

[@NVK85]

Ive bought my bike (v-strom 1000) last year and only now i found that previous owner removed secondary valves! The problem is that Suzuki does not sell them as spare parts, you can only buy whole assembled throttle body for 1000USD. And now if i even want to put them back, i can’t. Just because these valves are not available :(

[@britishskiing]

Great vid mate. I’m using a set of K2 gixxer 600 bodies on a car engine. As my ECU doesn’t account for the secondary butterflies would you recommend I remove them?

[@dirtygarageguy]

Yes remove it - its practically blocking the port

[@benwatts7214]

Can you do a video on butterflies in the exhaust. I have a BMW s1000xr and it has one. I was thinking it's for noise limitations. I have read it open from 5000rpm and up. Great videos

[@peterlindvall7671]

The exhaust valve closes off at low rpms, to give you more bottom end torque. I'd leave it alone, unless you install a full exhaust.

[@solomonbro7996]

😂 I like this guy, he’s funny af.

[@jdamage68]

No all motors suffer from removing Secondary butterflies.. zx14 is a good example of this. But I also use a power commander and tune.. But It gets 91-93lbs of torque at or around 2700-3200 rpm.. Which is unrideable on the street.. Much more for drag racing..

[@GeorgeFafa]

How is it unrideable on the street?

[@jdamage68]

Wot Da Fok there is no traction control and if your in a turn and you slightly flick your wrist, you’ll lose the back end and slide out or high side. You can avoid this a bit by installing power commander and a 280-300 tire kit. But with the 200, it’s dangerous to ride it like that.

[@Popsm0ke]

@@jdamage68 .....haha are you joking? Maybe you don't need to be riding a zx14. Real riders don't need wheelie or traction control

[@OneFreeMan17]

@@Popsm0ke rEaL rIdErS

[@Popsm0ke]

@@OneFreeMan17 ....say what ?...jdamage68 sounds like a 🤡 He definitely doesn't need to be on a big cc motorcycle, giving the advice to run a 280 or 300mm tire to keep from losing traction in a curve is asinine. Traction and wheelie control give people a false sense of confidence and puts them in situations where they are over their heads when the shouldn't even step over a mud puddle

[@davidallen6468]

I fucking love this channel

[@yogi2.057]

Absolutely, it's best NOT to make impromptu engine mods and attempt to outwit the factory moto engineering teams e.g., fooling with or removing a factory secondary throttle body, which is program FI for precision for precision throughout the bikes power band. Leave it.

[@milan512500]

Just in case if my ECU got problem to STV, I've removed the STV then the problem is solved. So then, re-tune the bike with whatever piggy back brand (PC/bazzaz) have in market, so, is that ok? OEM ECU quite expensive to replace it.

[@beachboardfan9544]

How about removal of exhaust air injection or PAIR valves on newer bikes... cant remember if you've already covered this or if I saw this on a bike forum.

[@dirtygarageguy]

That's coming soon with the SV

[@SwampCityRadio1974]

My Suzuki SV650S 2003 has been hesitating and backfiring at 3000 revs which coincides with an increase in the fuelling at 3000 rpm as indicated by the "dealer code" readout on the dash. I pulled off the air box and I could see that as I increased the revs the secondary butterfly valve was sticking/not moving and I could see a flash and hear a detonation in the throttle body indicating a backfire at 3000 revs. Is there a stripped gear somewhere in the actuator/motor that drives the butterfly valve? Is there something other reason why the secondary valves aren't moving? Would removing the secondary butterfly valve be a temporary fix til I order a new throttle body assembly/actuator etc?

[@dirtygarageguy]

The STVs have a positional sensor (a potentiometer) just like the TPS. Check that that works

[@SwampCityRadio1974]

@@dirtygarageguy Thanks mate. I ran out of patience and time to check systems "upstream" of the STV's so I removed them to confirm whether the hesitating and stalling was related to incorrect operation of the secondary valves. After removal the backfiring, hesitating and stalling disappeared immediately. It's very tempting to just leave them out. It's my only way of getting to work so I don't have time to work on it like it's a project bike. For now at least, I've solved the problem. I'm noticing a little less engine braking and low down torque but I can't confirm whether that's true beyond my own impressions. I'm not suggesting any one else do this, that's just how I solved my rough running issue.

[@MrRyan6616]

Pretty simple to put them back if it doesn’t work lol.

[@brentsmith4394]

Brilliant

[@ronaldoinline]

Hi there, great video! If I ended here you will guess that I was about to mess wih my STV. Some bikes as my zx6r will close the secondary butterfly when its reaching the top end of the power band, some ECU reflash maps open the secondary valves at 100% when the rider is at WoT, my question is why does the secondary butterfly starts to close at the end of the power band? And is it ok to reflash it and set it to open 100% when originally the ecu closes it at higher rpm's? Thanks.

[@dirtygarageguy]

To limit the load at max rpm. Load or resistance is what causes things to break. First they used rpm limits, next they reduce the power after peak torque.

[@dirtygarageguy]

He reason is that in reality no one is using that on the road.

[@ronaldoinline]

@@dirtygarageguy I'm converting my bike to be a track only machine. So for track use only can I open it a bit more than the stock values on my ECU? I've added velocity stacks, dna air filter and a full exhaust system. The bike is now working rich, so I thought maybe adding more air will be healthy. But the problem that I'm concerned is, what if my ram air system increases too much pressure in my air box... How much is safe to open it to gather 1 or 2 hp versus the possibility of blowing up an engine, that's my concern as when testing on a dyna we can't actually get the ram air to its working pressure. Thanks a lot for your opinion.

[@dirtygarageguy]

What bike is it?

[@ronaldoinline]

@@dirtygarageguy zx6r 2021

[@GILSJOURNEY]

I was having an issue on my 03 kawasaki z1000 where the throttle body would not open up after a little while causing the bike to stall and shut off. I bought several used ones on e bay and they all had the same issue so I returned them. Here in the states I cannot find a new throttle body at all and apparently kawasaki has them on back order with no eta in sight. This seems to be a common problem on this bike. I did not remove them however I did follow a different video and tricked them into staying open. My bike has been running fine since I did the mod I haven't noticed any low power issues while riding and I only stay at high rpms in the canyons otherwise on the street I ride pretty passive. I am either going to get a power commander or have it tuned. Any advice you can offer would be helpful. Thank you.

[@benyarwood7335]

Alright man what about if you use a delete module? Leaving the actual secondary butterflies in place? My stva is giving me headaches and I don't have the Dosh to take mi bike to the dealer

[@spacezoon]

Hey man. I've always had mine removed on all my race bikes with a Dyno jet and good tune. I've never had a problem at all. I've just had my z650 2021 go in for a tune and it's gone from 67hp to 84hp with a custom airflow box and exhaust system. Think people do it without tunes thinking they good to go

[@dirtygarageguy]

Problem? What?

[@screener545]

You are somewhat right but also very wrong. (you were right on the reason why they put it there "velocity modifier" but wrong on removing it. Unless its a track machine and not boosted you dont need it) Removing them actually WILL increase power mid to high and give back that throttle response real riders want in the low end (where you actually use the bike on the street) This is a great tool for a naturally aspirated race machine that is going all over the rev range. On the street I rarely go past 8k rpm so why would I want to ruin all my low rpm ride-ability? (aka throttle response and sure its been dyno proven to vary torque +-1ftlb in low end and increase throughout the rest of the rev range.)

[@dirtygarageguy]

"Removing them actually WILL increase power mid to high and give back that throttle response real riders want in the low end (where you actually use the bike on the street)" - proof. Your lacking proof - show me some and I'll do a video on it. "On the street I rarely go past 8k rpm so why would I want to ruin all my low rpm ride-ability? (aka throttle response and sure its been dyno proven to vary torque +-1ftlb in low end and increase throughout the rest of the rev range.)" - I think its funny because this is what STV's do - they increase low end.........

[@dalecarpenter8828]

Thanks ! I did understand and thank for the info ! Just foken with ya !

[@WickedTRX]

do the secondary butterflies also act as an idle control on any bike? like having the main butterflies always be a tad open at idle, and have the secondary regulate it?

[@dirtygarageguy]

They can do yes, and on more modern 3 cylinders it kinda required

[@WickedTRX]

The Workshop now I'm curious! Why not a common idle bypass valve on the 3 cylinder?

[@barryforster-r3k]

Removed secondary butterflies from 07 zx10r from new huge increase in power low down 175bhp top end still going strong 45000 miles later my 2017 zx10r feels flat as a fart in comparison guess what I'm doing next. 😁

[@johnphilipcien9403]

Hey did it work out for your 2017? Let me know🤣

[@barryforster-r3k]

2017 didn't have secondary butterflies, got it flashed at hilltop motorcycles 201bhp at back wheel. 2007 still more power below 8k.

[@fredlewis4432]

Does a CV Carb do the same thing mechanically?

[@dirtygarageguy]

Similar but not the same - more on this later

[@DeusBelli76]

Why is it that with a ECU flash they leave the secondary's open? Isn't that the same as just removing them?

[@dirtygarageguy]

We're going to follow-up on this, I've already recorded the video just need to edit and post

[@gsxrgen2682]

DeusBelli76 good question

[@TheLordstrife]

Wouldn't these secondary throttle valves essentially be computer controlled restrictor plates? Don't they use them to smooth out low engine surges on bigger cc bikes like the Concours 14?

[@veljaivanovic76]

Mine 650 is stuttering when I'm trying to accelerate at exiting from the curve. Sometimes when I give it ON the throttle there's no response few seconds and it seems choked then sudden snatch with acceleration... very unpleasant behaviour. Is it fixable by sub.plate removing

[@262fallguy]

Where did you get your mechanics degree? Because this is the first thing I do to every bike I've owned and I have zero issues? Sv1000,gsxr1000 and many, many others.

[@dirtygarageguy]

Where did you learn to understand english, did I say you have anything more than zero issues?

[@262fallguy]

@@dirtygarageguy you sir are a joke.... and you still didn't answer my question

[@dirtygarageguy]

I got my mechanical degree from Leeds University. You didn't answer my question.

[@262fallguy]

@@dirtygarageguy I speak plain English... I however do not speak fucktardo... so maybe I misunderstood something you said?

[@ninjanelly3506]

Holy shit.....think you need to cut down on the red bull dude!😮😮😮That intro😂🤣

[@yamabushisama]

Thank you this vid helped me from making a mistake

[@subdermalstain6397]

My zuzuki sv1000s 2006 got rain on. Then it stopped to work. Everything works BUT My top butterflys are locked wide open and i hear the gas pump but i dont see any gas squirting in the carbs. Yes injectors are cleaned. Is this issue a posible sensor somewhere or the lil top butterfly motor thats attached to its side?

[@shermanshelichannel6540]

Why did suzuki put them on their 05/06 gsxr 1k but not on the newer 1k's with the drive by wire throttle?

[@dirtygarageguy]

Because the drive by throttle does throttling automatically

[@shermanshelichannel6540]

@@dirtygarageguy just so you know I love your technical approach to everything. So much better than cause bike go brrrap

[@DanielMRamos]

Matt, I bet you all of this talk about removing the secondary butterfly started with people reading about what FIM allows as far as modifications on supersport bikes. I was reading the list they provided for the 300cc class a while back and I believe they specifically talk about allowing the removal of the secondary butterfly valve. Why street-Rossi wannabes think this is a good idea for their bikes is beyond me. It's apples and oranges.

[@supersonic3588]

I bought a K4 600 with these removed and the bike is dog shit to ride. All you can do is pin it, there’s no control pulling off!

[@alexschmitz49]

I came here for the lesson and left with a whole new love for the word fuck 🍻

[@Tacbi0325]

Hey bro my secundary trottle spring is Brocken !! I have to buy all trottle or just change new spring ??? Please helpme!!!

[@dirtygarageguy]

See if you can find a new spring

[@theresahafful-tz3el]

my bike keeps misfiring ... i need help i am running a 750 engine on a 600 body and ecu any help

[@jordanleonard8198]

If you remove that shit like someone did to mine it runs the bike rich and it will back fire and fuck up the engine and exhaust after a while. The throttle body needs those plates you will also need to dyno the bike I believe and fix the mapping.

[@ra666lf]

i have an vf500f and noticed when i go whide open throttle from low rpm and then close it a little bit it suddenly has more power. is this the same principe??? mfg ralf sorry for my bad writing ;)

[@dirtygarageguy]

This is the lag from throttle input to the carbs, the air acelerates as the throttle opens and then when you shut it down the mixture goes rich then lean, which means high combustion temps and more power - briefly.

[@ra666lf]

by the way great music taste

[@CaptainCarling]

Funny because I've been led to believe that tuning on the zzr1400 requires opening the secondary butterflies to max quicker and therefore creating loads more midrange torque 🤔

[@jcperez6228]

I've seen dynos on gsxr where the hp hits a sudden drop due to secondaries closing early as well. He's half ways correct ...

[@josepaco5099]

@@jcperez6228 hey you think if I remove it on my 01 Gsxr k1000 it would have more top speed?

[@jcperez6228]

@@josepaco5099 you know I think it just depends on the bike itself, you can try it maybe tune it a bit see if it works out for you. It may turn out well if it doesn't than just put them back on bro...

[@jcperez6228]

@@josepaco5099 in my opinion about the top end it probably will help top end but it may be a bit more unstable on the low end maybe lose a bit of power down low too

[@nmsmitto]

What was your intro tune? I forgot that band the album was good.

[@dirtygarageguy]

Machinehead - violate

[@nmsmitto]

The Workshop cheers man. I was 17 when I last heard that, almost 20 years ago.

[@codelicious6590]

That was a very clear and explaination, thanks.

[@turdledive927]

But the pressure is the same, you're just losing flow rate or increasing velocity at best. At low speeds, velocity is less important any ways. It probably just levels the torque curve.

[@wgfurman]

You make some interesting points. I do wonder if there aren't exceptions in design parameters to your conclusions. One of the most respected tuners for the Bandit line (Dale Walker of Holeshot performance www.holeshot.com ) recommends removing the secondary butterflies in conjunction with a new ECU, O2 sensor bypass and air filter box mod to drastically improve performance, increase throttle response and smooth out the torque and horsepower curves. www.holeshot.com/images/suzuki/bandit/650-1250/dynocharts/1250_dynochart02.jpg I'm fairly certain that given his reputation and longevity in modifying this one range of motorcycles that he's not falsifying his dyno results. Do you believe there's more at work in this situation or is there another reason he would claim this is the preferred change for performance? Just wanted to see if I was missing something. Thanks! Cheers

[@dirtygarageguy]

I believe this is to do with all the other changes not the STV's - just removing them ususally decreases low end torque

[@wgfurman]

The Workshop that would make sense except he does list both Dyno results for with and without the butterfly removal on his site.

[@dirtygarageguy]

Where? Do you have a link?

[@wgfurman]

The Workshop www.holeshot.com/images/suzuki/bandit/650-1250/products/efi-supertune-pro/dynocharts/1250_dynochart03.jpg. Stage 1 and Stage 2 are the same with the exception of removing the secondary butterflies and adjustment to injector timing. Smoothed out the curve and cleaned up throttle response.

[@peterlindvall7671]

@@wgfurman It looks like it was only worse very briefly, right off idle. According to my butt dyno, my KLX250 runs a lot better with the O2 delete, no secondary, Powercommander 5 Fuel Controller, race filter, and full FMF. The throttle response is better, with zero lag.

[@redmansen8530]

cars even have it to.

[@who_is_john_galt]

Hey Matt, have you seen the new crf250r engine? Are you eventually gonna make a video about it? It seems to be very nice, in fact, the whole bike is fucking awesome.

[@mrpearce1979]

You're a fucken legend!

[@slowvag8v]

Wouldn't a single computer controlled throttle butterfly do the same thing?

[@lillnemo1]

It does, but those bikes didnt have electonic throttle yet. The dude literally tells you in the vid

[@stevebrooks8625]

this guy doesn't know what he's talking about. i removed mine from my 2009 SV650s and WOW! It is a whole new bike. Runs like a scalded dog now. Way more power throughout the entire RPM range!

[@dirtygarageguy]

Prove it. Oh and one other thing, the motor is know to wear out it's bearing making them not open fully on the 650. Yours was probably broken if it made that much difference.

[@Puffalupagus360]

Why would you want to make your bike run shittier by removing the secondary butterflies?

[@SwampCityRadio1974]

If it's the difference between your bike not running at all and getting it back on the road again.

[@Puffalupagus360]

@@SwampCityRadio1974 nope because that's gonna set it up to fail on you at the most inopportune time.

[@SwampCityRadio1974]

@@Puffalupagus360 I removed my secondary butterfly valves because it was already failing to run with the valves in. It was stalling, detonating inappropriately and bogging down. With valves removed it runs perfectly. Not disagreeing with you, this is just my experience.

[@kevinfletcher7471]

Good vid enjoyed that explained a lot cheers

[@ciarangoldrick4121]

what was that song at the start . sounded noice

[@dirtygarageguy]

violate - machine head

[@dalecarpenter8828]

Yeah pull out the butterfly flaps but don't do the fuel managment or a bigger air cleaner or 2into 1 headers or the 200 rear parelli tire or the bigger front pulley or the smaller rear pulley and more than likely burn not premium fuel ! But yeah it's the butterfly flaps or whatever he called them !

[@picklerick2324]

Fucking love this guy

[@RB26N]

All valid explanation for low-mid RPM BUT when they close it off at top near RPM limit , that makes no sense. when you see 600cc , 1000cc bikes on dyno if they are supposed to make max power at say 14k RPM according to manufacturer the restriction closes throttle at 11k or so RPM and you lose whopping 30-40 hp on some 1000cc This what ECU flash removes. but when you don't have option to do ECU flash because no one does it properly in non -first world countries then this is best option for enthusiast to remove stupid restrictions.

[@dirtygarageguy]

The throttle bodies close at the far end of the revs to stop the valves from failing. The throttle bodies reduce the air but maintain the fuel level. This helps cool the engine, saving the valves from failing. This is usually used on engines with titanium valves because titanium has a lower thermal conductivity than steel alloys.

[@RB26N]

@@dirtygarageguy okay that makes some sense , since more open throttle body at high RPM means more power = more heat. but lets take an example kawasaki zx4r , claims max power at 14.5k RPM so on dyno you should atleast see power climb up , near that RPM level but the power graph stops climbing way before that on US and Canada specs zx4r stops at 11.5k RPM similar thing happens with other high performance bikes. basically its not engine related issue or anything its pure restrictions put on by govt infact on official kawasaki canada website it say "The Ninja ZX-4R and Ninja ZX-4RR reach max power at 11,500 rpm in Canada due to noise regulations." If you look at ecu flasher named 2 Wheel DynoWorks video for zx4r video it proves that. kzbin.info/www/bejne/b4ibdapunJmfiaM as he opens up restrictions and corrects horrible AFR the bikes get much closer claimed horsepower at rear wheel mind you, all stock as well. im sure dual throttle bodies are cool if done properly but they serve regulations more than performance.

[@dirtygarageguy]

@RB26N there is a difference between engineering and government ruling. But governments have to specify why and what laws are in acted. So at such high rpm, which law applies to this?

[@sebaalge6674]

Okay, i'm gonna put them back, when my bike is happy, i'm happy.

[@leegriffiths97]

What about on the exhaust side Matt, exup valves and the like? Is it just the same concept, to speed up the had flow?

[@leegriffiths97]

Typo *gas flow.

[@dirtygarageguy]

Yes and no, a bit more involved - video coming soon

[@leegriffiths97]

The Workshop my exup valve used to stick open or closed on occasion and the difference in the lower rev range was huge. I look forward to the vid. Missed you last week mate, good to have you back.

[@soundsfrench]

Please mate, a vid on exup's. I have a Fazer 1000 and people are always suggesting to remove the valve cos it's heavy and it can stick, blah blah. But mine's never stuck so I'm basically debating its weight over performance. What do you reckon bud? Ps. I like the twin power bands around 4K and 7.5k and I don't wanna lose any midrange.

[@rushiiiop]

I might have to do this to my 990 adv, there is no way i can get a used stepper motor to replace the one that is fu#$& on mine. probably it's time to let go my little girl :c