Is injected always better than carburetors? Most say yes, but is that always true?

[Wanderer]

Yes, there are benefits to injected bikes over carbureted bikes:

- No need for a choke.
- Better performance.
- Smoother idle.

But what about maintenance issues and costs? Can you work on it yourself? Or does it require expensive shop work? Computer module control.

Are there any benefits to owning carbureted bikes over injected bikes? Why own a carbureted Ninja?

I would love to hear the answers from our forum experts on this issue.

[Wanderer]

To my simple way of thinking, the problem with fuel injection is the ECU.

As long as it works, it works quite well, but if it doesn't, repair usually means repair by simply replacing expensive parts that few know how to modify, troubleshoot or debug.

Maybe that is all a good thing in today's plug and play world.

No more fine tuning, craftsmanship knowledge required or skill. Just plug in a new module.

As long as you can afford the new parts.

Maybe most see this as a slam dunk decision. I may just be showing my age... *smile*

[Flying]

Woah there. Fuel injection has opened up so many avenues in tuning because of how finely we can control fuel delivery.

Launch control, lean burn, AFR smoothing, control over knock, etc. is all possible given that you have the knowledge and skill regarding the hardware/software.

[Zaph42]

There is absolutely no reason for carburetion anymore. None. Some old timers will stick by it because that's what they know. And I'm not going for this "I can fix a carburetor by the side of the road" bs either. Decent fuel injection will not have anyone on the side of the road in the first place.

That's my opinionated entry on the subject.

[adouglas]

Carbs perform just fine, all else being equal. No need for a choke... so what? Let it warm up while you put your helmet on and go. Smoother idle? None of my carbureted cars or bikes ever idled poorly.

I agree with Flying, though. FI simplifies your life once you start doing stuff like tuning and makes it possible to explore more advanced engine management.

[choneofakind]

The nicest thing about fuel injection isn't any of those things listed, Wanderer.

If you live in an area close to the mountains and are regularly riding up and down large differences in elevation/temperature, it validate's its existence right there.

Don't forget that with carburetors, you're missing out on all the modern widgits and whozits that are great for making big bikes more approachable and safer in poor weather conditions. Traction control, wheelie control, launch control, power maps, etc. There's some aftermarket options for traction control (I think), but that's not OEM, so it has higher odds of being the culprit for stranding you on the side of the road (which defeats the whole purpose) than an OE ECU.

I have carbs. I don't mind them. Most of my riding is done within similar elevations and I'm handy at tuning them/cleaning them/making them run well and I don't mind a jet swap for the colder end of the riding season. But when I rode in and out of the mountains, they were a sloppy mess that caused all kinds of annoyance and iffy throttle response. Check mate.


Besides that, think about this realistically; how many miles do you have on your car? Did you make any modifications to the fueling? Likely no. There are plenty of motor heads out there who modify their car's fuel mapping/hardware in this modern age of fuel injection, but the vast majority of drivers do not. How many miles have they gone without their ECU leaving them stranded? Sure, cars do have their issues involving computers, but realistically the odds of that aren't high. How many countless stories of "help me! My carbs are dirty and my bike won't start!!!" have we read on these forums?

Now compare that with cars. Larger number of users. Larger number of miles per user (I'm assuming). Few issues per capita involving the fuel delivery system (I'm assuming).

[Racer x]

Carbs have worked perfectly fine for a hundred years. If you have them and tune them they work perfectly well. Fuel injection is better but I would not trade on for the other. If you don't like carbs buy a fuel objected bike. If you want to tune and modify things carbs are a little more flexible. But depending on the system that may not be true.

Personality I am a fuel injection technition and have worked on fI since it was mechanical without computers. And I work with fuel injection and know what to do with it. To a point. I'm not a person that can create a computer program . But I know what an engine needs to run properly. My race bike is carbs. My daily driver is fuel injection.

[Zaph42]

Originally Posted by Racer x

Carbs have worked perfectly fine for a hundred years. If you have them and tune them they work perfectly well.

When was the last time you saw an air/fuel ratio that was a flat line on a carbureted bike? Even a perfectly tuned race bike? No carb will ever work "perfectly well". At best, a carb might qualify as getting the job done.

Ok, well... I should probably bow out of this thread before people start throwing chairs at me.

[Racer x]

You are correct . The fuel injection is better and more adaptable. But getting the job done is what it is all about. My daily driver is fuel objected. I ride in in temps from -13 deg to almost 100 deg. I would not even try to start a two stroke carb bike in the dead of an Iowa winter. 90 mpg also. There is no way carbs can do that.

But I just like the carbs my custom ninja 250 and my race bike . They are simple and easy to tune. And get the job done. . But tuning two carbs is easy. Tuning four in another story.

[Triple Jim]

Originally Posted by Racer x

I would not even try to start a two stroke carb bike in the dead of an Iowa winter.

I rode my H2 through a couple winters when it was my main transportation. It always started like clockwork in the cold, normally not lower than 15F or so in the DC area, but I have no reason to think it couldn't go lower.

[greg737]

Well, that about wraps it up for this month's round of "Somebody please tell me that banging rocks together to make fire is easier/better that turning up the thermostat".

[JohnnyBravo]

Eh yes

[LittleRedNinjette]

[Ducati999]

The only thing I would add to all the posts above is that FI is just as easy/cheap/ complicated to change/adjust/tune as carbs. I have downloaded (for free legally) many programs to adjust programming. I have also taken apart and rejetted multiple carbs. There is about the same amount of BS involved with either one. FI is nice because once you have the software and cable (if necessary) there is nothing else to buy and less disassembly of the bike to make changes but it is much more complicated. Carbs are more labor intensive as you usually have to remove them and disassemble to make any change. You also have to have multiple "jets" available plus "needles and other parts. You need to drain fuel, remove and disassemble change parts and reinstall just to see if you even got close to what you want. With my SV650 (sold now) all I had to do was remove the seat, connect USB cable and change what I wanted (even with the bike running) and then go ride to try it out. My 916 is about the same. My wifes Ninjette 250 I have to remove fairings, seat, drain fuel...............you get the point.

The thing is lots of people are more likely to remove screws than to learn new software. Once you are past this point there is nothing too hard to deal with!
Hope this helps
Ant

[Racer x]

Just to be clear. I do think FI is far better than carbs. It's the changing from carbs to fI that I feel can be challenging.
Banging rocks is not as good for starting fire as rubbing sticks.

[cadd]

I don't know if this has been mentioned before, but whatever pros carbs bring to the table, one con will deter me from ever getting a bike with carbs again....winterizing.

Up until now, the 300 is my first bike with FI. Holy sheet....the winterizing process couldn't be any easier. All my previous carb bikes required draining of the bowls. Then, on a 65 degree weekend in Feb (like this coming weekend), if I want to take the bike out, I would have to prime the carbs, start the bike, go for a ride....then drain the freaking bowl again when I'm done because I know I won't be expecting to ride it until April.

The only pro I can think of with carbs (and I don't know if this is all in my head): the on/off throttle is smoother. Going from idle, to just cracking the throttle open just a tiny bit seems to be smoother. The on/off throttle of my 300 is much more abrupt compared to my 2nd gen 250. And if I remember correctly, my Honda F4 was smoother as well during the on/off transition.

But I would take FI anyday of the week without hesitation. Two identical bikes from the showroom. If the one with FI costs $1,000 more, I'll be willing to pay for it.

[JohnnyBravo]

Originally Posted by Racer x

Just to be clear. I do think FI is far better than carbs. It's the changing from carbs to fI that I feel can be challenging.
Banging rocks is not as good for starting fire as rubbing sticks.

That depends on which rocks you have to bang together; some are pretty good at starting fires with way less rubbing

[jkv45]

The majority of my bikes are carbed, but my daily-driver is F.I.

I see carbs as needing more attention and fine-tuning to be at their best. Temperature or elevation changes can have dramatic effects on carburation, as can different types of gasoline (with or without ethanol). F.I. is going to compensate for you, and you'll never notice any changes.

As long as the carbs are tuned properly they are going to be very good, but that may mean making adjustments to the idle mixture, idle speed, and possibly jetting to get it right. That also includes draining the floatbowls if it's going to sit for any amount of time, even with fuel stabilizer.

I don't mind it, and like the challenge of getting it right, but it's more dinking around than most people are prepared to do in this day-and-age.

[allanoue]

Originally Posted by Racer x

Just to be clear. I do think FI is far better than carbs. It's the changing from carbs to fI that I feel can be challenging.
Banging rocks is not as good for starting fire as rubbing sticks.

Originally Posted by JohnnyBravo

That depends on which rocks you have to bang together; some are pretty good at starting fires with way less rubbing

Flint is way better rubbing sticks.

[adouglas]

Originally Posted by JohnnyBravo

That depends on which rocks you have to bang together; some are pretty good at starting fires with way less rubbing

True, dat.

[Motofool]

Originally Posted by choneofakind

The nicest thing about fuel injection isn't any of those things listed, Wanderer.

If you live in an area close to the mountains and are regularly riding up and down large differences in elevation/temperature, it validate's its existence right there.........

How carburetor-fed airplane reciprocating engines compensated for the dramatic changes in altitude and temperature?

[Dave Wolfe]

Originally Posted by Motofool

How carburetor-fed airplane reciprocating engines compensated for the dramatic changes in altitude and temperature?

The same way as most fuel injected aircraft engines
Typically there is a manual mixture control which is adjusted by pilot

[adouglas]

Correct. There are also "turbo-normalized" engines. In those, the turbocharger is not there to boost power. It's there to maintain manifold pressure as the plane climbs. At low altitudes a turbo-normalized engine is no different from a normally aspirated one.

[choneofakind]

Last I checked, my Ninja didn't have any of that witchcraft.

[Racer x]

Originally Posted by allanoue

Flint is way better rubbing sticks.

If you have flint that is good. I'm fresh out. If you don't have sticks then the chance of fire is also sorta limited. Of corse gasoline ,flint and an old tire would definitely preclude sticks and wood. I guess urban survival is different survival in the woods.

[cadd]

Vaseline & cotton balls.

[MLR]

Originally Posted by greg737

Well, that about wraps it up for this month's round of "Somebody please tell me that banging rocks together to make fire is easier/better that turning up the thermostat".

Whats all this witchcraft stuff with rocks, I believe the best way is to wait for a lightning storm to start fires, then simply keep some kindling going in an animal horn for instant fire when you need it.

No need to envoke the wrath of god by using some new fandangle Blackmagic with rocks.

Anyway, So there was this one time, I caught the ferry over to Shelbyville. I needed a new heel for my shoe, so I decided to go to Morganville, which is what they called Shelbyville in those days. So I tied an onion to my belt, which was the style at the time. Now, to take the ferry cost a nickel, and in those days, nickels had pictures of bumblebees on 'em. Give me five bees for a quarter, you'd say. Now where was I? Oh, yeah — the important thing was that I had an onion on my belt, which was the style at the time. You couldn't get white onions because of the war. The only thing you could get was those big yellow ones

[rgx107]

For me it's the reliability and lower emissions with FI, but also the precision from injectors fed by a pressure-regulated rail. You could hang the bike upside down and the exact same amount of fuel would still be injected - for a short while until the pump is empty. A carburetor is dependent on the gravitation, so the amount of fuel depends on whether you are accelerating or decelerating, ascending or descending. I have read that it can vary as much as 10%, the carburetor experts on here can probably elaborate on this. Maybe it partly explains why it's so popular to tune the carbs for richer mixture, which masks the effects of varying mixture somewhat.

[Z1R rider]

Originally Posted by Dave Wolfe

Typically there is a manual mixture control which is adjusted by pilot

The Model A Fords (and probably others) also have a knob under the dash to turn to adjust the main jet, pull it out for choke, rotate to adjust mixture. The hardest part of tuning carbs is finding or making the parts you need, that's why Holley's are the go to carb for performance autos.....parts galore!

[Motofool]

Originally Posted by rgx107

......A carburetor is dependent on the gravitation, so the amount of fuel depends on whether you are accelerating or decelerating, ascending or descending.......

That is why the main jet is located by the middle of the bowl.

Are weed-eater carburetors dependent on the gravitation?

[Motofool]

Originally Posted by Dave Wolfe

The same way as most fuel injected aircraft engines
Typically there is a manual mixture control which is adjusted by pilot

More on the subject, copied from
https://en.wikipedia.org/wiki/Fuel_i...nd_development

"Direct fuel injection was used in notable World War II aero-engines such as the Junkers Jumo 210, the Daimler-Benz DB 601, the BMW 801, the Shvetsov ASh-82FN (M-82FN). German direct injection petrol engines used injection systems developed by Bosch from their diesel injection systems. Later versions of the Rolls-Royce Merlin and Wright R-3350 used single point fuel injection, at the time called "Pressure Carburettor". Due to the wartime relationship between Germany and Japan, Mitsubishi also had two radial aircraft engines utilizing fuel injection, the Mitsubishi Kinsei (kinsei means "venus") and the Mitsubishi Kasei (kasei means "mars")."

Originally Posted by adouglas

Correct. There are also "turbo-normalized" engines. In those, the turbocharger is not there to boost power. It's there to maintain manifold pressure as the plane climbs. At low altitudes a turbo-normalized engine is no different from a normally aspirated one.......

[Motofool]

Why have carburetors coexisted with mechanical fuel injection since 1902 and with electronic fuel injection since 1957?

[Racer x]

I would say money. First there is a perception carbs are easy to live with. That is because people fear the unknown. And early systems had some issues.
Second is cost per unit. That is the price point and what people will pay for something. I guess

[Snake]

FI all the way! Embrace modern technology. It's our friend.

[Wanderer]

Originally Posted by Flying

Woah there. Fuel injection has opened up so many avenues in tuning because of how finely we can control fuel delivery.

Launch control, lean burn, AFR smoothing, control over knock, etc. is all possible given that you have the knowledge and skill regarding the hardware/software.

I'm not arguing with you. I just am trying to learn why injection is a better choice.

Great post!

[Wanderer]

Originally Posted by Snake

FI all the way! Embrace modern technology. It's our friend.

I am starting to doubt that...

[dcj13]

I’ve had the good fortune to grow up with carburetors and traditional ignition systems (points and condenser). I still have one car with carburetors (’75 TR6 with twin constant depression carbs), one bike (KLR250) with a carb, and one bike with fuel injection (’94 BMW K75). Both systems have their advantages and disadvantages.

Fuel infection is great! Until something goes wrong. With FI, you have the computer, the ignition module, hall effect sensor(s), mass airflow sensor, FI relay, idle switch and/or throttle position sensor, temperature sensor, fuel pump, fuel pump relay, fuel pressure regulator, fuel injectors, one or two oxygen sensors, and a buttload of connectors, cables, wires, and contacts. A whole bunch of things, any one of which will cause the bike to run poorly or not at all.

Now add a rough environment, including vibration, mechanical shock, electrical shock (including jump starting), thermal cycling, altitude changes, humidity, water exposure, months of inactivity, ham-fisted maintenance, and on, and on. Lots of opportunity for failure.

Carburetors? They’re simple in comparison! If the bike’s not running right, all you gotta do is run some Sea Foam or Magic Marvel Mystery Oil in a tank of gas to clear things up. If that doesn’t work, you carefully clean the thing (or send to Ducatiman). Damn near anybody (you, me, most of this forum) can get them working OK eventually. It’s not rocket science.

And just wait until your fuel injected bike is a few years old… The technicians at the dealer won’t know WTF they’re doing and will suggest throwing $100 bills at the problem by replacing stuff until it works. And no OBDII diagnostics (present on all cars since 1996) for us shade tree mechanics. And (just like bikes with carbs) who the hell knows what the meathead previous owner monkeyed with. Oh yeah, almost forgot: fuel injected bikes (and cars) can have snatchy throttle response (abrupt response).

FI has lots of advantages over carbs, but it’s no panacea.

[dcj13]

Originally Posted by Motofool

Are weed-eater carburetors dependent on the gravitation?

Typically not. The fuel tank is slightly pressurized.

[Wanderer]

Originally Posted by dcj13

I’ve had the good fortune to grow up with carburetors and traditional ignition systems (points and condenser). I still have one car with carburetors (’75 TR6 with twin constant depression carbs), one bike (KLR250) with a carb, and one bike with fuel injection (’94 BMW K75). Both systems have their advantages and disadvantages.

Fuel infection is great! Until something goes wrong. With FI, you have the computer, the ignition module, hall effect sensor(s), mass airflow sensor, FI relay, idle switch and/or throttle position sensor, temperature sensor, fuel pump, fuel pump relay, fuel pressure regulator, fuel injectors, one or two oxygen sensors, and a buttload of connectors, cables, wires, and contacts. A whole bunch of things, any one of which will cause the bike to run poorly or not at all.

Now add a rough environment, including vibration, mechanical shock, electrical shock (including jump starting), thermal cycling, altitude changes, humidity, water exposure, months of inactivity, ham-fisted maintenance, and on, and on. Lots of opportunity for failure.

Carburetors? They’re simple in comparison! If the bike’s not running right, all you gotta do is run some Sea Foam or Magic Marvel Mystery Oil in a tank of gas to clear things up. If that doesn’t work, you carefully clean the thing (or send to Ducatiman). Damn near anybody (you, me, most of this forum) can get them working OK eventually. It’s not rocket science.

And just wait until your fuel injected bike is a few years old… The technicians at the dealer won’t know WTF they’re doing and will suggest throwing $100 bills at the problem by replacing stuff until it works. And no OBDII diagnostics (present on all cars since 1996) for us shade tree mechanics. And (just like bikes with carbs) who the hell knows what the meathead previous owner monkeyed with. Oh yeah, almost forgot: fuel injected bikes (and cars) can have snatchy throttle response (abrupt response).

FI has lots of advantages over carbs, but it’s no panacea.

My point exactly! Thank you!

[Triple Jim]

An interesting point has been raised by dcj13. Fuel injection became pretty much necessary, to meet fuel economy and emissions requirements, and does indeed have the ability to improve things in both these areas. Other advantages, posted above, include flexibility in modifying "maps", which can be both easier and less expensive than re-jetting a carburetor.

But there is a lot more complex electronics and sensors involved with fuel injection, and more complexity does really mean less reliability. I don't know anyone who was stranded on a long trip because a carburetor failed, but I do know people who were stranded and had to get help getting to a dealer or parts supplier because their vehicle computers or a sensor, etc., failed.