Carburetor vs Fuel Injection - Why Motorcycle Riders Should Think Again 

You forgot the most important bit. Carb makes me feel like a pro mechanic when I clean it and the bike starts lol.

Tip: for carburetors, when done riding if bike is not going to be ridden for a few days just shut off the fuel and let the bike idle until the carb is dry/stalls. Then there is no ethanaol fuel in the jets to clog things up.

After all these years of trying to grasp carb technology it turns out I didn’t need a smarter brain, I needed a better teacher. Thanks Fortnine, we love you dearly

This guy could make learning anything fun, but he chose a topic that's already fun and made it more fun

My Air Force carb training was a 2 hour class with test at the end....you condensed that carb course into a minute or two, without losing any content...53 years since I took that course.

Those kids deserve credit for either great acting or for dealing with your technical gibberish. Don't get me wrong, I love that gibberish.

Is anybody else interested in a video, where Ryan simply shows his bikes, their "stories" and what he changed about them?

I find carburettors amazing. If you take the time to tune the set up, they just do so well across a whole range of conditions. As for the fuel clogging up after a few weeks, I just drain the bowls if the bike is going to be parked up for any length of time. If longer, just add some fresh fuel to the tank and mix it in before turning the fuel tap back on. Give me carbs any day!

I am completely dumbfounded by the brilliance of this video! Finally a clear, concise, and enormously entertaining explanation of fuel systems for the layman with the bonus of learning the differences between car and motorcycle applications. Unraveling the mystery of fuel injection mapping was particularly interesting. And tailoring it all to the Halloween theme was nothing less than creative genius.

I've been watching Ryan F9 since I was in 8th grade. I graduated just last year and finally got my lisence and bought my first motorcycle. FortNine really helped me learn the ins and outs of riding before I even got on a bike. Thanks guys.

I've used to have an inline 4 with carbs (Suzuki RF600). I've mastered the cleaning, rebuilding, setting (syncronisation, and setting the pilot jets correctly(!)) the carbs during the time I've owned the bike. And also the religios way to drain the fuel from fuel bowls before the winter break... There was also a starting procedure, how much choke you need in the current temperature/humidity/engine temp from previous running. It was fun, like the bike had habits :D I've switched to a fuel injected Honda VFR800 VTEC. You just start it in every possible environmental condition and it just runs. Always with the same rpm, and always sounds the exactly same, without any hesitation. Much more simple, much much more reliable, and also a little bit boring to be honest. Just fill it up with (euro) 100 gas and leave there for the winter, starts up instantly at spring lol. I love modern technology but missing the romantic side of old style things. :D I'm also not missing the struggle to maintain the carbs at the same time

the subtleties in these productions are incredible. the traffic "honk" when cutting to the car scenes, acting as a perfect intro for the speaker. he even acknowledges them with his verbal cadence. what a privilege to watch.

One of my favorite lines from Click and Clack, the Magliozzi brothers, was that if you rebuild a carburator enough times, you will wind up with enough left-over parts you couldn't figure out where they went to build a complete new carburetor.

Yep. Another masterpiece from F9. Well done Ryan and team!

I was saying my vows at my wedding when this video was posted so I told my still fiancé that I will be back after watching Ryan F9

When I used to race two stroke minimoto, it gave me an appreciation for two-strokes and carbs, as I learned to work on both. The problem was when you spent Saturday learning the track and setting up your gears and and carb to be optimized for the track and current conditions, only to have a massive weather change over night making your carb setup sub-optimal on race day.

If you think Carbs are simple, try jetting them with a Turbo.

Well, actually for me, an old guy who is 15 with 50 years of experience, after having worked on both carbs and fuel injection on both autos and motorcycles, they both work, and as long as you use the fuel regularly out of the tank, they stay relatively clean. But like you said, with ethanol fuel, water can mix with the fuel since alcohol absorbs water, and you get goo, which can plug up both systems, not to mention crystalizing the fuel lines. So it's the fuel thats the issue, not the delivery system. Out in the field or on the trail, and with the correct tools, I can and have repaired a carburetor and finished my ride for the day. But with a malfunctioning fuel injection system, I can't even leave the garage. So for me, I'll keep the block of aluminum with simple holes drilled in it. I can poke guitar strings thru the holes, clear it, and enjoy moto therapy for the rest of the day.

My first four bikes were carbureted. My current bike is 20 years old and fuel injected. It's been 20 years since I've had to clean a carburetor before I could ride. I'll stick with a fuel injected. Please put out more videos!

Excellent as usual - and funny too. One point not mentioned though is reliability. A carb is essential a clever passive system. As long as all seals are OK, passages are clean, adjustments are made and stable, it will work. EFI will also work as long as all electronics / sensors do - which we know to be a potentially tricky business....

On the cons of EFI, if you're worried about the "accuracy" of the fuel mapping table, you could search and send the bike to a qualified tuner who can either 1) reflash the stock ECU according to your bike or 2) get aftermarket ECU and tune it, which also would make it easier if you want to use different air filter & exhaust in the future. Also can be fitted with multiple maps depending on your usage (daily ride, track day, drag?). Don't mind spending more money? Get a wideband O2 sensor and aftermarket ECU that can utilize it, and you can pretty much fit any kind of modification to your bike. Plus with certain ECU, like Tuneboss or Aracer you can install app on your phone to get live data logging, and see all the sensor readings. Which make it easier to troubleshoot if your bike are having problem on the side of the road. I used and dabble a lot with both of them. I worked at a workshop involving heavily modifying the bikes (which isn't really usual for most riders), and in my experience EFIs are far more easier to manage. If we replace the head and block cylinder + piston to be bigger, fit a different camshaft profile, bigger valves, bigger exhaust pipe, and if we did it on an EFI bike, I would just send the bike for dyno tuning when we're done (maybe fit a bigger injector or throttle body if needed, usually the tuner can tell). On carb bikes on the other hand, we would have a massive headache for the next few days trying to match the carb sizes, and then have to match the main and pilot jets trying to make the bike run happily at all RPM range. But then again, at the end of the day it's much more satisfying to see when the carb bike finally run like a champ. On stock bikes, that would depends on the owner. Some people like tinkering and servicing the carb, and consider it as routine. Some just like to press on the start switch and ride, and don't want the hassle of having to service the bike when it won't start. Some people, like me, want to utilize the "extra" features that EFI bikes can provide. Choose whichever you prefer. It's your bike and you're the one riding it.

I finally got all my 4 carbs (one for each cylinder) tuned and synced perfectly. Took a few years to master setting float height, air/fuel mix, synchronizing with a manometer, jet sizes, needle height and cleaning/rebuild. An interesting experience to say the least. The most valuable lesson I have to share is a JIS screw driver is your friend.

My guy, this was an amazing explanation! I, for one, am quite the car geek and I found myself working for a motorcycle company in the spares department... Completely unnecessary information, BUT, I found myself to be so ingrossed in this video as it answered every thought I had after you laid out the facts! Absolutely enjoyed this video! Keep doing what you do man! We Love It!

Man that shot in the end of the kids walking away was awesome..........symbolic!

I liked the video, but I have to say that this time you got it partially wrong. You are right only if you consider old generation efi. It's been years since manufacturera started putting lambda sensors in bikes. It allows for continously correcting the fuel map in different air conditions. An example? the efi in a 2003 sv650 works as you described, but since 2007 the sv650 has a lambda sensor! Also an efi allows you to do much more than just getting the optimal stoichiometric ratio, things that a simple carburetor can't do, like changing the ignition/injection timing when opening/closing the throttle in different ways, thus allowing different behaviors if you accelerate/decelerate fast or slow, and much more!

I’ve went my whole life confused about how Carbs and Fuel Injection worked due to intimidating and hard to understand explanations. Thanks Ryan for the much needed clarification in an entertaining and understandable way!!

This is without a doubt the clearest explanation of a carb and how it works I've ever seen or heard. Thank you.

I'm 61 now but remember dismantling my motorcycle carburettor and doing the usual repairs all from the manual that came with the bike. How the great have fallen. Admittedly we're dealing with far more complex modern machinery but your average dual sport or single cylinder commuter isn't so. I was in my teenage years working on these motor bikes so I'm guessing it's assumed that we're no longer useful. Great luminary this fella! Thanks for an illuminating explanation!

Absolutely love your channel bro. I'm 52 years old been riding most of my adult life yet my knowledge on the subject has easily doubled due to watching your videos. I highly recommend your channel to all my friends who ride .please keep them coming and keep the rubber side down

Never thought I'd be comparing those two ever again but F9 comes along and reminds what pulling a Knob was like. EFI for me thanks 😄

I tell people they need to retune for their full exhaust and they say “no my O2 sensor will do that” 🤣 ok bubs

I absolutely LOVE your videos! That being said... I've broken down with fuel injection, and I've broken down with carburetors. I'd much MUCH rather break down with a carburetor. Also, carbs absolutely ARE simple when you understand them.

I played with my carbureted bike more than I played with myself. Does that make me the one out of 10 that didn't make Ryan's majority? Damn. Bring me an EFI bike then...

EFI is only an improvement in that you don't have to fiddle with fuel delivery, whether it be local weather, or altitude changes on a cross-country trip. Motorcycles have averaged 40mpg for at least as many years, and everyone usually runs to lean, or rich, same as the old carb days. It's rare to find anyone that takes the time to properly tune their motor.

The greatest thing about carburetors is the ability to take advantage of the stupid. I can’t count how many old motorcycles and watercraft I have purchased at ridiculously low prices, or even had given to me, because the owner rode it for the summer then just parked it for the winter and, surprise, it won’t start the next season. All his clueless friends did the same thing so the dealership is full and taking months to get to it, so he sells it to me for pocket change. I clean the carb and wave to the former owner as I ride past. Fuel injection threatens to put an end to my little scheme. I hate so called “progress”. I might add that I have an 81 year old car that runs perfectly, no fuel injection, no computers, so little wiring there’s not even a fuse panel. I wonder how many 2021 vehicles will still be operational in 81 years, or even able to be restored, because of all this progress and advanced technology.

Just got my first injected bike, and so far love it. I ride regularly from 4500 ft to 10000 ft, and I get good power delivery regardless of altitude.

"the fuel jet is precisely the width of your cojones."-killer line

I hope you never stop making videos bud. Everyone is better and better. Your editing skills, content, and witty delivery is top notch. You should be proud.

Those kids at the end said it all without saying a word... "we don't care, just give us something that is fun to enjoy" Sir, you and your crew are complete geniuses. Well done to all involved.

Best motorcycle channel bar none.

The production quality on this is amazing for just a video explaining carbs vs fuel injectors on motorcycles.

Hey Ryan, we haven't had a "motorcycle mods/accessories" video in a few years. With Christmas coming up, any chance we can get an updated list of your favourite biker gifts/gadgets? (whether bought by others, or ingeniously bought FOR others knowing they'll just give it to you because they don't want it)?

"Hit the gas" is still accurate because "gas" has another meaning beyond gasoline...🙃

A few days ago, rain poured heavily and I borrowed a flat screw to remove water in my carb. I feel like a pro mechanic that day.

God your videos are soooo good I can’t even wait for the next one. Everything from the content to the scripting, filming, editing, sound effects just top notch!

The production of this show is just so insanely good. Man what a constant joy to watch!

This was a great video. Good job of explaining how things work. On newer cars I have to say the fuel injection is so much better. It calculates just the right mixture for start up and for driving. Cars now days start so fast you might not know your battery is on its last leg until it won't crank the engine. That happened to me. I started up at home, drove to a town 20 miles away and visited a store. When I tried to leave the engine barely turned over and then, NOTHING. Thankfully I was at the store where I ALWAYS get my batteries. I pulled the battery out and saw it was 8 years old with a 7 year warranty. Guess I got my money's worth! My 2000 Harley with carb never had a fuel problem. But, I always looked for alcohol free gas and I shut the petcock off as I roll in the driveway. By the time the garage door is at the top the engine is almost out of fuel. But for winter storage, I add twice the recommended amount of Sta-bil and make certain that reaches the carb before I turn off the ignition. I don't run the carb dry for the winter but as I mentioned it is soaking in the Sta-bil fuel stabilizer. That carb has never been off the engine for servicing. It is now 21 years old and has 85,000 miles on it. Twice a year, I run one half can of sea foam through the gas tank.

Another excellent video! I have eight carbs (8!) on my Vmax, and I have ridden from the coast of California, through Texas right through Denver up to South Dakota with zero noticeable changes in performance or fuel consumption. There's over 60000 maintenance free miles on those carbs. I don't think carburetors are nearly as finicky as people are led to believe. Just don't let them sit lol! As always, your mileage may vary. Cheers!

I'm just here to appreciate the amazing cinematography and storytelling 👏

I like carburetors because the more analog feel makes me feel more connected with the vehicle, and the lack of a computer results in instant throttle response. Now if only I could figure out how to tune them properly…

In less than 8 min you helped me understand the basics of carb versus fuel injection … thank you

Jetting has become a lost art but as a young man I didn’t have the $ to run to the shop every time my bike needed work. I’m thankful for that now. Cool vid, thanks

I grew up with carburettors and had so many issues with them. But you just accepted it, did the work on them and carried on. But not having to spend an entire day pulling the bike apart to get the carbs out, sort them out, then put it all back again, tune and balance them is a big advantage. I've got an old classic I tinker with, but I'm thankful those days are gone.

The gaze those two kids make while waiting is priceless :) Great video as always

Ryan F9 has taught me more about motorcycles & components than I’d ever thought possible! Call me a weirdo but I love this nerd shyt! Keep ‘em coming sir

Thanks for explaining the theory of fuel map logic, the difference between having carburetors and fuel injection, and why motorcycle carburetors gum up. I worked in the IT industry for almost 40 years. I did everything from designing and writing apps to fixing hardware. In my many years of testing apps I have found one constant. Programs contain logic problems, even after rigorous testing. Ever have your check engine light turn on and the mechanic can't find the problem, or it is misdiagnosed? Of course you have. Don't assume that that computer is working perfectly, because it is not. In the IT industry the saying goes" Assuming makes an ASS out of U and ME". Rely on your skills more than the vehicle.

The production as always amazing. This channel needs 100 million subs

Fuel injection for me, thanks. I just want it to work whenever I want to ride-not the other way around. Lol

Thanks for the tip, I'm lucky enough I have a ton of gas stations in my area that sell ethanol free fuel. It's more expensive but I'll definitely be putting that in my bike from now on.

I live in México, so carburator motorcycles are still really commom here (also with small cc engines). It's usually the higher end bikes that use FI

One minute in, and it's already pure art.

Carbs were also easier to tune for the shade-tree DIYer. All you needed was your butt on the seat as a dyno, a set of carb-sticks to sync them, some needles and jets to experiment with, then you were good to go. Anyone with a weekend of spare time could dial them in better than stock. Of course the only problem besides them needing attention whenever they sit for awhile, is that changes in temperature, humidity, or altitude dramatically effects a carburetor's state of tune, requiring adjusting them with each season if one rides year-round.

Same engine in two of my bikes(Yamaha R6), one with carburettors, set up properly on a dyno, one with fuel injection, never been touched. The fuel injected bike absolutely blows the carburetted bike out of the water. It's smoother and more responsive on the road and the track. No messing with choke and totally reliable for the last 19 years! I'll never get a carburetted bike again.

'Some people find it inconvenient to pull their knob once or twice a day but nine out of ten men don't seem to mind'. Gold.

Every video yall make is a cinematic masterpiece! Well done once again

Been teaching my son's jetting,live in one of the highest towns in Canada, rich smaller jets, summer thin air, fall denser air it's a good lesson,rejetted the old xr and the cfr and they're shocked at the difference carburetor tuning makes.

40 years riding/wrenching and in the late 90s my experience with fuel injected bikes was unpleasant, i.e., flat spots scattered across rpm range (BMW GS), fuel pumps, Motronics, etc. I found that carbureted bikes generally ran better but required painstaking efforts when modifying for performance and helpful knowledge passed on by previous tinkerers. No bike should sit for 4 weeks during the riding season. That’s negligence 😉. Balancing the fuel/air equation was a flashback to chemistry classes. Another great video!

I absolutely love the thought of FN just explaining all this to two random elementary schoolers who knocked on his door.

The finest mix of education and entertainment. Great as always!

One thing he didn't touch on was throttle response difference from a carb to injection. From my experience I've always felt a major difference between the feel an engine with a carburetor vs that same engine with an injector. Always wanted to learn why that is because it is my primary reason for preferring EFI. But nevertheless an incredible video as always!

There I was removing the 842 pieces from my carb. Thinking about the one piece throttle body on my EFI bike and it got me thinking. I wonder if the reason many people prefer fiddling with a carb is that… look! A blocked jet! Well clean it or replace it. With EFI, if it doesn’t start, you blink for ten seconds like Homer Simpson, break into a cold sweat and cry in the corner. A lot of riders are scared of electrics. “Can’t be fuel, look, the injectors are spraying……..”….. yeah but have you checked the pattern!!!! Well… okay… maybe it’s the sensor…. Which!? well…. Oxygen, temp, crank, camshaft, TPS, CPU. Mapping, ABS, seat temp, heated grips, ZZZZZZzzzzzzzzzzzzz 😏😁

I feel like this guy should be a director, as much as I love motorcycles this lad seems to have the right mind. Attracting peoples attention in a quite articulate way that pulls you to be intrigued and to listen more. Great vid

Having ridden since the 90s, I've had my fair share of carbed bikes. I worried when injectors started appearing - what if they went wrong? After all my carbs would go wrong regularly but I could fix them, but I could do nothing with injectors. That's still true, but the truth is I haven't needed to. They're an effing god send.

All modern motorcycles has a lambda sensors as well as cars do and it allow motorcycle injectors adjust mixture on the fly. Hardcoded fuel maps was used in case of failure of some sensors and FI light will turn on at this case.

I have to say, and I’m sure many will agree… the quality and research that have goes Into your videos are simply amazing. I’m studying motorcycle mechanics at college and your videos are really helping clear the things up the things I don’t understand. Cheers 🤙🏼

finally a video that made me understand how the carb works.

"The main jet is exactly as wide as your cajones." Awesome line fellas!

I tuned the carb on my dirt bike to perfection for my conditions. Mountain riding between 4-6k feet above sea level. It was a 2 stroke and I used premium gas mixed with quality synthetic oil. It was not terribly difficult and once it was tuned, the bike ran flawlessly every time.

Apart from all the positive promotion that went with fuel injection, I always understood that the prime (and not spoken about reason) for the wholesale change to F.I. was the catalytic converter. That carburettors, no matter how good couldn't prevent unburnt fuel going out the exhaust and poisoning the cat on overrun. Where as the fuel injector instantly goes no fuel on overrun thus no raw fuel out the exhaust. But then what would I know, I ride a Niken!

Really a good video explaining how both the carburetor and fuel injection work. Really easy to understand.

Greetings from turkey, i can easily say that you are the king of social content makers i have never seen that much work, editing and content iq etc… respect

Wow! Excellent production but more importantly excellent explanation. It's said if you truly understand something you can explain it simply. You guys totally understand this. Thanks for breaking it all the way down!

I really like the cinematography here. This sure is high quality

The production and narration is so good, it would definitely give big movie production houses a run for their money.

My favorite setup was on my KZ900LTD. It had 4 carburetors one for each cylinder. Tuning it was an art. But once tuned it was poetry.

You left out one key part of F.I., the O2 sensor which measures the O2 in the exhaust stream. This allows the ECU to adjust the pulse width of the injector. A simple carburetor can not do that. Changes in temperature, humidity, and fuel quality can not be accounted for with a carb, meaning, sometimes, the bike is rich, sometimes it is lean, and on some occasions, it is running stoic. Note that an engine should always run slightly lean to allow a more complete burn. When run at Stoic, there isn't enough time for every fuel molecule to find the correct amount of air which leaves some unburnt fuel leaving the engine.

Omg... the Charlie sheen reference was hilarious. I'm weak! 😂

Until I learned the WinPV software from Dynojet and learned to utilize the Powervision and wideband 02 censors correctly, electronic fuel injection was one big frustrating mystery. Now that I understand fuel injection I love it.

I thought I was done with chalkboards after my scholastic years, little did I know. Ryan your videos are very informative and F'n Hilarious! Huge props to you and your film and editing team. Always looking forward to the next F9 video. best wishes. ✌🏍

After recently inheriting (well, having dumped on me) an old Leyland DAF van with an SU car I was honestly shocked how ridiculously simple they are to work with. Sure its not perfect in every situation like EFI, but my god it makes the entire vehicle feel so simple when there's only 10 wires and buckets of free space because its not a zillion components, wires, sensors and fuel lines smashed into an absurdly small package

I love my fuel injected 100th Anniversary Ultra Classic Electra Glide. I only had one problem one time with the fuel injection... and that was the servo motor in the throttle body went bad. It was replaced under warranty. Which brings me to this point. Sustainability. I believe that the more our motorcycles stray from the basic elements of design, the less likely that we will be able to enjoy them for many years. The range of years that any part on a motorcycle will fit, is getting more narrow as time goes on. This means that it is less economically feasible for the original manufacturer to supply any particular part, or for a third party manufacturer to decide that there is enough of a market to make that part. So the ECU, various sensors, electric fuel pump, throttle body, injectors, etc. will be hard to get. Any one of these items can be responsible for a problem with the fuel injection system. For a carbureted bike, all you needed was a rebuild kit for the carb. Maybe a jet kit. Maybe we should just budget a new $40,000 motorcycle every few years.

Had the same issue many complain about after a foot injury. Didn't ride the bike for a while. I used stabilizer, octane booster, B12, etc. It eventually works, but you have to ride through at least 20-30 miles of your engine feeling like it's gonna shake apart before it goes back to normal. I suppose the only way is to find refined gasoline with no ethanol, probably exists on the black market, at $50/gallon, but the health of my pristine 32-years old classic Honda 750 is priceless 😎

Absolutely brilliant! Thanks F9

Like always, i feel a bit smarter and happier after a educating video from FortNine :)

The spookiest part of this video is how well it explains how the carb and choke work in simple terms

Fuel maps are now setup to produce the lowest emissions not max power . So buy something like a power commander and get it set up properly ,your bike will be much more responsive .

Thank you so much for making those gems Ryan and team, its pure pleasure watching those clever and witty videos.

Usually the information in these videos is pretty good but this one is almost completely wrong. Carburetors were always going to be fazed out for several reasons. Fuel injection is much more friendly to packaging constraints. The throttle body doesn't care how it's mounted but carburetors do. You can only mount a carburetor in certain positions. You can only go so big on a carburetor before it won't meter properly at lower throttle positions. That's why you usually don't see motorcycle carburetors above 41mm. The bigger the carburetor the less vacuum to draw the fuel in at lower throttle positions and that's one of the reasons why they put accelerator pumps on the bigger carbs. Fuel injection doesn't have that problem and it got to a point were the carburetor was limiting power. Also fuel injection is constantly making adjustments according to your weather conditions even on pre 02 sensor bikes. Yes it has a base map but it also has atmospheric maps. If you have a 02 sensor then it's making adjustments on the fly usually at the lower throttle positions. It will adjust the fuel trim based on emissions afr. Also direct injection in cars is the result of emission requirements not for performance. It allows for performance at extremely high emission standards. Overhead injectors work better for high rpms and that's why most sport bikes have two sets of injectors. One lower set for better part throttle response and overhead injectors for half to wide open throttle. Even some automobiles are using direct and port injection combinations. Also fuel injection was starting to be used in motorcycles way before ethanol was being used extensively. It wasn't till 2007 in united states it started to be used nationality and a few years later it was mandated. Most motorcycles had fuel injection by 2003 except for certain classes. Ethanol can mess up fuel injection too but it's easier to clean out fuel injection in some cases. Carburetors served their purpose just like points did but their time has passed. Fuel injection became a standard because of enhancements in engine technology and emission standards increasing. Also the fact that advancements in computer technology allowed the ECU to be small enough to fit on a motorcycle. That's why most of this video is misinformation.

Solution: Spend a little more and buy non-ethanol fuel. In Canada you can still get premium that doesn't contain any ethanol at a lot of gas stations. Plus it's easy to test the fuel for ethanol. It really saves a lot of headaches in any small engine.

Injector Fuel maps are just the beginning. The ECU constantly adjust those maps with short term (non-stored) and long term (stored) trims to those maps based off feedback from engine sensors. Don't forget that a carburetor basically has a fuel map too. Only difference is that it's a mechanical one based off it's design, fixed and cannot make on the fly adjustments (for temperature, altitude, engine wear, etc.) like fuel trims do with injection.