HOW TO TUNE A CARB / CARBURETOR (step by step guided)

[Applause] [Music] [Applause] [Music] what's up you guys today we're learning about carburetors everything you need to know about them how to tune them what each component does how it installs i'm going to teach you everything this can be a very confusing subject carburetor tuning but it doesn't need to be if you understand how one of these spray bottles work then you can understand a carburetor all we're doing is getting that mist perfect inside the carburetor let me show you exactly what i mean i spent a ton of time and effort getting these little diagrams made for you guys to teach you how to tune your carburetor so if you could do a spinning back flip onto the subscribe button and hit the little blue bell that's right on the side so you can get notified when new videos like this come out let's get started we're going to be tuning this gy6 honda ruckus that has a pwk slide style carburetor it doesn't matter if you have a motorcycle atv car it doesn't matter if you have a carburetor these concepts will apply there's a few terms that you should know when we're dealing with carburetors just because if you're talking to somebody or somebody's talking to you about carburetors then you guys will be on the same page so lean would be not enough fuel characteristics of a lean condition on a carburetor would be a bog you go to give a full throttle it's like that's too lean not enough fuel stoic that would be perfect the carburetor is running absolutely perfect no hiccups and then rich rich means too much fuel so when you go to give it gas it's going to be like it's going to be cough and sputter and things like that the opposite of the bog lean not enough fuel so lean not enough fuel stoic perfect rich too much fuel so i've got the carburetor completely disassembled by the way this is a pwk slide style carburetor that we're working with all the pieces have been broken down and labeled so that i can tell you what they're called what the functions of each each piece is and then we can put it back together and you'll know exactly where all the parts go what they do and then we could dive into what components we need to switch out to make the carburetor run absolutely perfect so this is our carburetor body it's a completely stripped down version of the carburetor we've removed all the components i'm going to go step by step and i'll show you exactly how all these components go onto this carburetor so this is a pilot screw or air fuel screw i'll show you what i mean in just a second so you got the the screw it's kind of like a tapered looking screw and you've got a spring that goes on there the spring is on there so that you it doesn't vibrate basically you can call this a pilot screw or an air fuel screw if it's an air screw that little part where you install this pilot screw or air screw is going to be on the air filter side if this screw is more over on this side it's going to be a fuel screw the easiest thing to do is call it a pilot screw the more you back it out if it's a air screw it's going to be you're going to give it more air it's a fuel screw the more you back it out you're giving it more fuel so we'll just install that a good reference point would be to tighten this down until it's lightly seated so i just got it lightly seated and you're going to go half a turn one turn one and a half two turns for sea level turn in two and a half turns for high altitude that's just a general setting that you can set right out of the box that's not concrete at all i'll show you how to adjust that in a little bit next we've got the idle screw this is pretty self-explanatory this controls the idle so you got your little washer that slides right on there and then you've got your spring again the spring is so it doesn't vibrate out this just installs on the side like this and you really can't get this set you're gonna have to apply some pressure since it's got the spring you can't get this set until make sure you don't strip it it's a real easy finger screw you can't set this until you actually get the engine started so i just kind of get a few turns in there and that's the idle screw next we've got the choke pretty simple choke goes in and out like this the plunger and it is made for cold start so if your engine won't start up when it's cold you pull the choke a lot of times on this style of carburetor you won't even need these let me show you how it goes in right up on the top of the carburetor you'll see the little spot for it's pretty obvious because it's got the threads you just match them up and you just crank it down this is a 14 millimeter just get it nice and snug it's plastic so be careful we've got the needle jet here and the emulsion tube sometimes these two are together if they're together this is this complete assembly is going to be called the needle jet but since it's a two piece deal this is our needle jet and this is our motion tube this is the part that always ends up on the floor people don't realize it's a two-piece deal and let me show you why so the way that this goes in see that rounded part that's going to be facing like down towards the bowl just like this so if i drop it down in there like that and i get my emulsion tube out you don't realize it's two pieces and then it just falls right out that's the reason why you just have to be careful so again the machine end is gonna go down to the point whenever i look at the look through the carburetor if i look down the carburetor then it sticks through if i did it the other way it won't pop through so make sure you got it the right way very important so the emulsion tube or jet holder i'll show you why it's called a jet holder in just a second goes back right where we drop the emulsion tube in it locks that sucker in place so i'm just going to crank that down look like that and i need to crank it down with a wrench so let's go ahead and do that this is a nine millimeter just barely tighten it it's not like a serious titan because this is brass it'll strip really easy next up we've got the main jet this main jet goes right onto the jet holder of course just like this that screws in as well and this one is the six millimeter i just tightened it down barely okay and this is where our fuel is going to go through now a lot of people get confused on what a jet is i mean you think a jet you're thinking like an airplane or something something weird a jet basically is a screw just like this one with a hole drilled through a very precise hole so that's our main jet this is going to control three-fourths throttle to fully wide open next we got the pilot jet this controls the idle and it just installs in this circuit again your carburetor might be slightly different but the concepts remain the same so again a jet is just a basically screw with a hole drilled through it very precise the pilot jet is going to look a little different than the main jet as you can see and then you just snug these down they're just brass so you don't need to really crank the heck out of them just to dive into these jets since this is the most talked about part in any type of carburetor tuning is jetting this is the pilot jet the pilot jet you can call an idle jet you can call an idle circuit pilot circuit there's a few different terms but the bottom line is this skinny pilot jet that controls the idle to like quarter throttle and then you've got your main jet here and that's going to control the three-quarter throttle to full wide open so there and i'll teach you about the rest here in just a second but on the sides of the jet you will find a small microscopic number and that refers to that size of jet so if you need to go up or down if you're lean or rich then you can do that by say you had a 120 jet and it's too lean and you needed to go to richen it up a little bit then you go to like a 122 jet just for a reference so this is kind of a unit that needs to be assembled within itself we're not going to be doing a cable so to be a little bit different but this is our needle jet the needle jet is going to control a quarter throttle to three quarter throttle so this is like your main cruising circuit so what i'm going to do is i'm going to take the slide this is called the slide i'm going to drop the needle the jet needle in just like that and then you've got your cable lock or sink spring seat that'll go down just like that then you've got your spring if i push it down you'll see what i mean see that kind of locks in you can do it backwards like this then it doesn't go down all the way so make sure it's the correct way it'll slide down really easy and then you've got your cable top here so cable top cable cap whatever you want to call it then you normally you'd have your throttle cable coming up through the top and it'll lock in there let me show you how this goes into the carburetor it's like blocks when you're a kid you got to line it up so that at the same time that needle needs to go down into the needle jet hole you'll notice you'll know what i mean if you do it yourself but i'm going to drop it down it obviously didn't get caught up because it dropped all the way down since it's spring loaded i've got to push the cap down i'm just going to hold it down with my fingers like this and then you can get your screws started again normally your cable would be coming in from the top here so i'm just going to get it started by hand and then just crank it down so it doesn't come loose so by now we've almost got our carburetor completely put back together but there's a few more components that we need to put into the bottom here so we'll go from the bottom up actually so this is the float bowl drain this is your float bowl this kind of works just like a toilet if you know how toilet works this is this would be your like your the tank behind your toilet where the where the water is being held so i'm just gonna the cool thing about these carburetors is if i pull the float bowl drain off i can get to the main jet which is cool since i don't need to take the whole float off just tighten this down just nice and snug again this is the drain for the fuel so normally that's one piece i just had it apart because i wanted to show you what the two pieces how they went together this is your float imagine the back of your tank on your toilet how that works if you know how that works that's going to be the same concept then you've got your float pin which is this guy and then your float needle which is this let me show you how it goes on on the carburetor here's your float needle if you notice there's a little button right there if you had a clog carburetor that button wouldn't be pushed but what i need to do is drop that onto the float like this see how that works and then i'm just going to drop this down see i have this angled so it doesn't slide off the float i'm just going to drop that down like that and line those holes up there because that's where the pin is going gonna go i'm gonna slide my pin through there just like that and this is how the float operates if i go like this up and down that float needle is going up and down and as the see this carburetor is right side up so when gas comes in where this there's a cap over this but when the gas comes in and flip it around like this and take the float bowl off gas comes down through this hose right here in through this valve right here where the float needle is as it fills this float bowl up gas will start to make this float float up when it floats up it's going to kill the fuel so see how see where that's at this line right here with the line on the carburetor this is the proper adjustment that you need the final step is to install the float bowl on the carburetor so you just line it up sometimes it's a little bit tight and difficult it goes on like that and then of course two screws hold it on then you've got your hose for your power jet there's a small jet inside here and when you open this all the way open completely open if you notice it draws fuel from the flow bowl up into the what they call the power jet and see that little hole there that little hole supplies fuel at wide open throttle it won't start coming out of there until it's wide open and that's a complete carburetor we just assembled you can use this for cleaning your carburetor as well now that you know it goes together for reference this is how the carburetor is mounted you've got your air filter attached and it goes into your intake manifold which mounts to the actual engine and then you've got of course your throttle cable coming in through the top i know what you're thinking there's a lot of components in a carburetor but at least now you know what each component does where they go what it looks like now i can show you how to tune a carburetor let's do it now that you guys know what a pilot jet is a pilot screw and a jet needle and a main jet let me tell you what they do so you got your pilot jet that's going to be 100 percent your idle completely closed throttle to quarter throttle open cool thing is you got your pilot screw or air fuel mixture screw you can adjust that in or out to get that idle perfect once you've got that idle perfect you can adjust the actual idle screw down to make it idle correct your jet needle that's going to be your your main adjustment point you're gonna have a quarter throttle to three quarter throttle that's gonna be like your cruising circuit your jet needle then you've got your main jet that's gonna be wide open three quarter throttle to wide open all of these circuits overlap each other so it's super super important that you only do one adjustment at a time i always start my carburetor tuning with the pilot jet i get that so you know it idles you may have to do some pilot screw adjustments so that you can get that idle perfect then i do my wide open it might stumble and spit on the way up but if you can get it to wide open then you know your main jet is somewhat close and then i start working on my needle jet the cruise speed if you can get all those dialed in perfectly you'll have a perfectly running carburetor so to get to your jets you're if you're just doing your main jet you can remove that float bowl drain and you can get right to the main jet without removing the whole float bowl thing you have to be careful with is on these float bowls if you get gas on this o-ring it could swell up and it's hard to get back on so your main jet here this is going to be for the wide open three quarter throttle to wide open so you've got your main jet here this guy that's going to be three quarters throttle to wide open then you've got your pilot jet that sits right next to it it's kind of sunken in down there that's going to be your closed all the way closed to quarter throttle remember you can adjust your air fuel mixture on your idle circuit you can adjust that in or out if you get to the point where you're halfway down like you just have a half a turn until it bottoms out then you're going to need to change your jet if you back it out more than three and a half turns then you're going to have to change your jet that's kind of the range half a turn to three and a half turns now your needle you'll need to pull that out i showed you how to do that that sits inside the slide if you notice your needle has little bitty slots i have a drawing here these little slots you have to decide where you want to put your clip depending on the slot if you go up or down on the needle it's going to make it leaner or richer so if i go up higher on the clip the needle is going to go down which makes it leaner if i make the clip go down towards the bottom here then the needle's going to raise up which is going to make it richer you can buy different needles with different angles of this needle very subtle difference on the with the naked eye but that makes a difference too so you can play with those needles i won't get too far into that that's more for super fine tuning one huge huge thing that you need to know is jetting is always different it doesn't matter if you have two identical bikes jetting is generally always going to be different you're going to get it really close based on like your buddy that has the same bike as the same jetting but yours is going to be slightly different i don't care if it's a little air screw adjustment a total main jet change it's always going to be different so you can get a reference from online but that's not going to be the concrete answer elevation and performance intakes like air filters performance exhaust they all play a giant role in jetting so if you get a brand new exhaust system or if you get a new intake or if you went up from california to colorado or the altitude tire where they have less air all of this plays a huge role so you constantly need to be jetting and things like that that's why electronic fuel injection is such a big deal nowadays the technology is caught up a carburetor is basically a tape deck compared to an mp3 they still work great but you've only got four circuits to tune unlike an efi system they got about 30 circuits to tune you can really dial them in and it's all electronic like i told you i have this ruckus here we're going to tune it i'm going to i'm going to put all of everything i taught you into action and you can see exactly the sounds it makes what happens and how i do the adjustments let's do it one very important thing you need to check before you begin you need to have throttle free play turn your bars to the left and the right to verify that your throttle isn't being pulled in any way you should have a couple millimeters play when you turn your bars to the left and the right so you know the cable is not pulling the carburetor slide up so we've got our brand new carburetor in here this hasn't been started yet so i'm assuming that we're going to need to do some idle adjustments for sure and adjust our air fuel screw this does have a choke on it i'm gonna try not to use it a lot of times on this style of a setup you don't need to use the choke it starts right up so let me see if i can start it i might have to keep it alive with the throttle the hand throttle at first and then i'll adjust the idle actually it's decent so if i turn this that's going to uh raise the idle like that now this is our air fuel air fuel adjustment screw i'm going to turn that in or out it's getting worse so i'm going to go the other way until i achieve a nice smooth idle it's going up if you notice there's like a sweet spot here so kind of you find that middle range and then the idle's normally too high like it is right now i'm gonna turn this down and again i didn't use the choke at all so that's cool maybe a little higher on an idle on this particular model the gy6 you wanted 1800 rpm to 2000 i'm just going to let it sit here and warm up completely probably five minutes before i do anything else so it's nice and warmed up now if i give it a whole handful of throttle if bogs like that that would be generally speaking a lean condition that right there is a bog that's normally a lean condition if it was a rich condition you get like a stumble like it wants to rev but it's not but it is kind of a guessing game that noise you were hearing is a rich condition where it's stumbling like that so we just want to start from the very bottom and work our way up on the tune so we're gonna go for a little ride we can see if we get that main jet dialed in first we've got the idle jet set by ear really good we're at idle smooth things like that but what's it going to be like when we go wide open and then we'll adjust our cruise speed okay let's see what we got so i'm just this is a quarter throttle that's going to be on my idle circuit still order throttle starting to sputter just a little bit i'm going to just roll into this and see if we can get our uh so our true speed is definitely acting up for sure it's gonna be our needle so that sounds really good right now as it sits our idle jet is nice it feels good by ear our cruise speed is needs some attention so that's going to be our needle and then our main jet that seems pretty good as well so it's not stumbling it's not bogging so all of our focus right now is going to be on the needle left quarter throttle quarter throttle turn this piece around quarter throttle oh i'm just off quarter throttle just off quarter throttle we've got a fog right there i can feel it in my seat throttle there no backfiring so if you noticed whenever i let off the gas when i'm not giving any gas i'm on decel or downshifting i'm not getting any backfiring if i got backfiring then you know that i would need to go larger on the pilot jet because backfiring is a lean condition a lot of people think that that's a rich condition but it's not now if i come to a stop and my idol is hanging like it come to a stop it's like and then it slowly goes down then you know you know that you need to go larger on your pilot jet you need to richen up your pilot jet or sometimes you can adjust your air fuel screw to correct that so that mid-range felt like a rich condition so it wasn't a bog where it didn't just like die out but it was more of a stumble a bog would be more of a lean condition not enough fuel and a rich condition would be a stumble like you heard so it's a little bit of a guessing game if you're not running something called a wideband o2 sensor which makes life super super easy if you want to pull your spark plug out and you can check like you can cruise on it at the rpm that it's acting up and then you can pull your spark plug and look at the very tip of the spark plug and if it's really black it's very rich if it's really white it's lean and if it's tan color then it's a stoic it's perfect although with all the fuel additives it makes it very difficult to do plug readings like that nowadays let me show you what i'm talking about on this wide band that makes your life way way easier there's no guessing involved so this is the rolling wrench wideband o2 sensor comes with all the cables it comes with a wideband o2 sensor this gets welded onto your exhaust a lot of exhaust pipes already have a bung for the o2 what this does is it reads the gases coming out of the exhaust sends the signal to this gauge this gauge fits spits out a number and that'll tell you exactly what your air fuel mixture is so i'm going to hook this guy up and then we'll we can tell exactly if we were rich or lean there's no guessing involved which by the way can be found on our website i'll put the link down below and you can purchase one of those let's talk about afr ranges afr means air fuel ratio this is your operating range for running so as as your bike is running this gauge is going to show a number stoic is chemically ideal this is like if you have a car from the factory or a motorcycle or whatever this is going to be set normally to 14.7 that's good it's going to run perfect across the board now if you were at more like 11.5 which is more fuel you're gonna run even better like that's for performance somebody re-jet it for performance their their number is anywhere from 11.5 to 13.3 for performance now if you're just want fuel economy then you're going to be at like 16.5 now this number as you ride you're going to adjust your carburetor on all of the circuits that i talked to you about so that that number is right where you want it to be based on what your interest is um performance economy or just chemically ideal i have my wide band in welded in the exhaust with the supplied bung a lot of exhausts will already have this bung installed on it from the factory and i'm just running the wires this is totally just a temporary thing because i'm going to take this off when i'm done tuning got the gauge there and then i've got the power ran up to the trickle charger this takes all of the guess work out of this this is like totally worth the investment if you're doing any type of tuning on a regular basis otherwise you can do it by ear so i'm going to adjust the air screw air fuel screw i'm backing it out right now let's go a little at a time the more i back it out the leaner it gets i pretty much have it back out four turns that's not gonna work so that tells me that we need to actually go down on the pilot yet i'm gonna bring it back in as i bring it in it gets rich it's about as good as we're gonna get with that pilot and remember the pilot circuit is purely for idle i put it up on the bars here so we can see it easily so there's our little after quarter totally rich we're at 10 afr okay so we're on our needle right now 4.5 up and now we're going to go into our main main jet was even at 10.5 see how a wideband can help you now we know we're super rich and uh all the way across the board so we need to go a little bit less on the pilot a little bit less on the needle and a little bit less on the main you only want to do these one at a time but since i know what i'm doing i'm going to do all of these at once and revisit so i need to loosen the boot so that i can pop this carburetor off comes off pretty easy remember this is full of gas so the minute i tip it over it's going to start pouring gas out what i'm going to do is i'm going to open up this drain right here and then drain that onto a rag gas is going onto the rag there we go and that's how we uh drain the gas from the bowl so we can continue removing the bowl because remember what i said is there's a o-ring on the float bowl gasket that can deform and it's hard to get back in if you get gas on it so we always want to drain the gas first it's kind of cool you can get straight to the main jet real easy since this is like a racing style carburetor a lot of times when you go racing you're always switching out those main jets because you're always open wide open balls of the wall when you're racing so the main jet is the main circuit you'd be changing so i made it easier just to get to that but i can't get to my pilot or any of that so the whole bowl has to come off get this float bowl pulled off of here move that out of the way now we can get to our pilot jet and main jet we're going to go a little bit smaller this is kind of a trial and error so we're going to go a little smaller on the pilot a little smaller on the main jet then when we're done with that we'll open up the needle and move the needle clip just a little bit the pilot jet was a 38 this is a 35 a lot of times they'll that's how they'll go in like three step increments but we went smaller this should be perfect perfect perfect and we can adjust it out with the air screw we'll do the same thing on the main jet and pull that sucker out of there we had a 120 main jet in there we're gonna put a 115 in there at sea level that probably would be perfect but we're a mile above sea level in denver colorado so we need less fuel so we can put the carburetor back on because next we're just going to be dealing with the needle which is out out the top we don't need to actually have the carburetor off let me get the sink crank down if we wanted to we could try this at this point but like i said i do this all the time so i kind of know what i'm doing generally speaking you don't want to do two things at once only one thing at a time so you don't get confused so we'll just open the top up here so we can get to that needle once we get to that needle we're going to lean it out just a hair by removing removing the clip and moving it up one slot which will bring the needle down so pull that out i don't think i showed you how to do this so you're going to pull this up like this basically you're pulling the spring back and then you can pull your cable out you notice there's that little lock down in there where it locks into place so here's our needle here's our little diagram right now our needle is sitting in the number three clip and we want the needle to go down to kind of plug the main jet hole a little bit more so we're going to set that clip in the number two mark okay got it all set up slide it down into place this is a little bit of a trial and error if we went too far or not but the good thing is is we have that wide band and we can that takes the guesswork out of what our actual tune is i bet you were right on the money guaranteed so at an idle we're doing pretty good at like 12 afr at a cruise we're at like 13. 13.7 12.5 that is perfect so i think you guys got the picture pilot jet adjust the idle the air fuel mixture screw adjust the idle mixture once you get into the cruise speed the quarter throttle the three quarter throttle that's going to be your needle jet and high rpm is the main jet all four of those circuits are easily adjustable and if you do it the wide band and you have a little time then it makes life really really easy now let me show you how to tune a efi system a fuel injection system it's much much easier no hands-on stuff few buttons let me show you so tune a fuel injection system way way easier than a carburetor rolling wrench hand tuner we've got this one there's a lot of different companies on the market but this is all you do it's super super easy so by the way this is our 232 this one's a monster right now it's idling at 2200 rpm but check this out so all you do for a fuel injection no getting your hands dirty or anything like that this would kind of be like the pilot jet so i'm adjusting this all i do is push enter has been adjusted i've richened it up fuel injection system is way way easier than a carburetor throttle response on fuel injection is unreal i just wanted to show you guys the difference you're wondering why the engine sounds so clattery i know i'm going to get a bunch of comments on that that's a dry clutch so that's that noise you're hearing no motor problems that's the way it's supposed to sound that was an extremely long-winded video with a ton of info if you learned something make sure you comment down below what you learned and do a freaking spinning bicycle kick onto the subscribe button if you like the video hit the thumbs up button if you didn't like the video hit the thumbs down button two times i appreciate you guys and we'll see you in the next video

Channel: Rolling Wrench

Views: 264,258

Rating: 4.9409237 out of 5

Keywords: carburetor adjusting, carburetor jets, carburetor tuning, carburetor tuning 2 stroke, carburetor tuning motorcycle, carburetor adjusting screw, jets, main jet, pilot jet, idle jet, air screw, fuel screw, carb, carburetor, cvk, slide carb, diaphragm carburetor, how to tune a carburetor, rejet, carb rejet, carburetor jetting for high altitude, pwk, arf, air fuel, mixture, how to, bog, sputtering engine when accelerating, bog when accelerating, jetting, carb jetting help, needle clip

Id: rCo6dJAxi64

Length: 35min 44sec (2144 seconds)

Published: Wed Jun 02 2021