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

[Zaph42]

Originally Posted by dcj13

Fuel infection is great! Until something goes wrong.

Everything is great until something goes wrong. I've never had fuel injection go wrong. And I've owned a LOT of fuel injected bikes. The worst that has happened to me is taking a bike apart, and forgetting to plug in a sensor when I put it back together.

[Wanderer]

Originally Posted by 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.

I agree Jim and also how many people then have the ability to troubleshoot and repair their stranded bike once they get it home? What about specialized equipment required to do so?

Don't get me wrong, I am not slamming or attacking fuel injection! I am simply discussing the pros and cons of fi vs carb bikes. To be very honest, I personally know very little about fuel injection myself or how to repair it.

That is why I posted this thread. To learn from people here that do know how to repair and troubleshoot both types of bikes.

Thanks everyone for your posts here.

[Wanderer]

Can anyone comment on problems with fuel injected bikes that are stored for a season or even a few years compared to carbed bikes?

I would think that carbed bikes would be more susceptible to a gummed up fuel system after setting than a fi bike.

What have you guys found? How easy are each to prepare to ride again?

[jkv45]

Originally Posted by Motofool

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

Are weed-eater carburetors dependent on the gravitation?

Carbs on most small engines don't have floatbowls, they have a diaphragm that uses vacuum or intake pulses to supply the fuel.

[Motofool]

Originally Posted by jkv45

Carbs on most small engines don't have floatbowls, they have a diaphragm that uses vacuum or intake pulses to supply the fuel.

Exactly !!!

Those have a little fuel pump activated by the vacuum of the engine, which allows proper flow of fuel for any position of the carb.

[MLR]

To be serious, Im talking to myself.

My current car is FI (2015 WRX STI), my old 50cc scooter was FI, for daily duties, fuel consumption (emissions) and all round smooth delivery of power I believe FI is the best.

BUT, when it comes to modifications, to take my car for example, I have replaced intake and exhaust parts, I have also increased boost pressure, BUT, it was the tuner and a aftermarket ECU which ensured it ran without lunching itself.

Now for the old FI 50cc scooter, I played with the airbox by removing a snorkle on it one day, it wouldnt run above idle due to the different fueling, I replaced the snorkel and it ran normal.

Now for carbs, all it takes is a couple of washers and some jets and generally away you go, yes it may take a while to find the correct jet sizes but I can do it.

Basically, if you dont mind playing around you can modify the hell out of your carby bike and have it running well with a screw driver and some parts.

Or, if FI, you need to look at playing with or replacing your ECU and logging data to review and adjust to ensure your modifications are not lossing power, or pay for dyno time and someone who knows what they are doing tuning your bike.

FWIW, Ive seen quite a few FI and carb bikes and cars that have had modifications to the exhaust and intakes and without correcting tuning they have lost power or lunched themselves.

[dcj13]

Originally Posted by Wanderer

Can anyone comment on problems with fuel injected bikes that are stored for a season or even a few years compared to carbed bikes?

I would think that carbed bikes would be more susceptible to a gummed up fuel system after setting than a fi bike.

What have you guys found? How easy are each to prepare to ride again?

Toward the end of the riding season, I try to run the gas in the bikes (FI and carbed) down quite a ways, then top up with fresh gas, add some Stabil, ride it home, and put it away. Never had a problem upon reawakening the bike.

In the BMW early K-bike world, some of the guys have had problems with bikes that sat for several years. As expected, the problems are with stuff intimately exposed to fuel: the injectors; the fuel pump; and (less often) the fuel pressure regulator.

With early K-bikes, the fuel injectors can be rebuilt for about $30 each (they are automotive Bosch L-jetronic). A bad Bosch fuel pumps is really expensive, but clever guys replace it with a late ‘80’s Mustang pump for around $60.

[greg737]

I have a 2005 EX250 that I converted to fuel injection about 8 years ago. I used the Microsquirt ECU (version 2).

The bike runs great, I'll probably keep it until I can't ride any more (I'm 52 years old, so who knows how long that will be). But I have 2 other motorcycles, a 1993 Suzuki GSF400 and a 1999 Honda VFR800, so I split my riding time between these 3 very different bikes. The bike I take out of the garage totally depends on what kind of mood I'm in that day.

As a result the EX250 goes for months without being ridden (or even started). I do nothing to the bike between rides other than put it on a battery tender every so often. I never "winterize" the bike. Today I started it up for the first time since October and it started on the very first press of the starter button.

Fuel Injection wins because it wins.

[Triple Jim]

Originally Posted by greg737

I have a 2005 EX250 that I converted to fuel injection about 8 years ago. I used the Microsquirt ECU (version 2).

Very interesting. What gas mileage do you typically get?

[dcj13]

Originally Posted by greg737

I have a 2005 EX250 that I converted to fuel injection about 8 years ago. I used the Microsquirt ECU (version 2).

What did the kit cost? Was all the fuel mapping included?

[greg737]

Originally Posted by Triple Jim

Very interesting. What gas mileage do you typically get?

The bike gets very close to the same mileage it got when stock. Maybe one or two MPG better when I do more highway miles.

The problem with comparing this bike's mileage in a "before and after" sort of way is that when I did the fuel injection conversion I also put on an AreaP full exhaust system and I opened up the airbox. So the engine is flowing more air and can handle more fuel as a result.

So in one big move I went from the somewhat restrictive OEM airbox+exhaust+carbs to less restrictive exhaust+less restrictive intake+fuel injection.

[greg737]

Originally Posted by dcj13

What did the kit cost? Was all the fuel mapping included?

It wasn't a kit. When you go with a Microsquirt or Megasquirt setup you're really out there in the "do-it-yourself" world.

You have to cobble the system together with the various bits that make up a fuel injection system: I used a 2008 European EX250 throttle body+injectors (the 2008 EX250 was the very first fuel injected EX250, but only in Europe and Thailand. Through hard work, luck and a friend who lived in Stuttgart Germany I was able to get my hands on the throttle body from the first one that got totaled in an accident in England and sold off for parts by a "bike breaker"), for fuel delivery I used a Honda TRX Rancher fuel pump (it's one of their four-wheelers), for fuel filtration I used the high pressure fuel filter specified by GM for their Envoy SUV (very convenient because it has both the input and outflow on the same end of the filter which makes it easier to mount in the tight space of a small motorcycle), as already mentioned I used a Microsquirt ECU (it's the early "Version 2" model, they have a much better "Version 3" now that I used for my 1993 Suzuki GSF400 fuel injection conversion), I used General Motors spec sensors that are subcontracted by AC Delco and Motorola (the air temperature sensor, the coolant temperature sensor, the manifold absolute pressure sensor) because their output voltage curves are well known which makes them easy to use, I used a Bosch LSU 4.9 five-wire wide-band O2 sensor that I custom-mounted on the collector of the AreaP exhaust system (this sensor sends raw data to an Innovate Motorsports LC-1 wide-band O2 sensor controller which then sends air/fuel ratio information to the Microsquirt ECU).

There's more involved, but I guess that description is enough to paint the picture of the bike as it stands. I love tinkering with engines, I have a degree in computer science and I have plenty of hobby-money to spend. So I enjoy doing these things.

And I have no idea what the all-in cost of this project bike is. It was something I just worked on in the garage as a hobby-level diversion.

[jkv45]

Originally Posted by greg737

(SNIP)Today I started it up for the first time since October and it started on the very first press of the starter button.

Fuel Injection wins because it wins.

Well, I just started by carbed 1964 Dream that hasn't been run in over 20 years (probably closer to 25) and it started 1st kick - winning!

With fresh gas and a properly maintained fuel system, carbs aren't going to give you any trouble. It is going to take slightly more work to ensure trouble-free running. If you don't stay on top of maintenance you will quickly learn how to disassemble and clean carbs.

[greg737]

Originally Posted by jkv45

Well, I just started by carbed 1964 Dream that hasn't been run in over 20 years (probably closer to 25) and it started 1st kick - winning!

With fresh gas and a properly maintained fuel system, carbs aren't going to give you any trouble. It is going to take slightly more work to ensure trouble-free running. If you don't stay on top of maintenance you will quickly learn how to disassemble and clean carbs.

And that's how these "Carbs are better" forum threads usually end, with the carb guys "winning the internet" with an just such an obviously incontrovertible, thoroughly logical, bring-down-the-house, drops-the-mic-and-walks style post.

[dcj13]

It's hard to beat a hand cranked Victrola for reliability.

Sound quality not as good as a CD player, though...

[allanoue]

I stopped trusting carburetors after I had to walk home 2 miles when the carb on my 09 iced over one morning on my way to work.

Won't happen with my 300 FI

[Wanderer]

Let's don't forget a good reason to like carbed bikes, the sound!. *smile*

There is nothing like the sound of a bike with open carbs.

Get rid of that damn plastic air box, put on a K&N Pod air filter and you will think that you are listening to an old Triumph twin when it revs up.

Few bikes still sound like this.

[greg737]

Originally Posted by Wanderer

Let's don't forget a good reason to like carbed bikes, the sound!. *smile*

There is nothing like the sound of a bike with open carbs.

Get rid of that damn plastic air box, put on a K&N Pod air filter and you will think that you are listening to an old Triumph twin when it revs up.

Few bikes still sound like this.

I don't know that Triumph ever produced a two cylinder engine with a 180 degree crankshaft.

[allanoue]

Originally Posted by Wanderer

Let's don't forget a good reason to like carbed bikes, the sound!. *smile*

There is nothing like the sound of a bike with open carbs.

Get rid of that damn plastic air box, put on a K&N Pod air filter and you will think that you are listening to an old Triumph twin when it revs up.

Few bikes still sound like this.

Let's don't forget a good reason to like FI bikes, The air we all breath!. *smile*

My 300 with the AreaP long quiet core, sound magnificent.

[Wanderer]

Originally Posted by allanoue

Let's don't forget a good reason to like FI bikes, The air we all breath!. *smile*

My 300 with the AreaP long quiet core, sound magnificent.

Is a correctly tuned carburated bike really more polluting than a fuel injected bike?

I suspect that the main reason that FI has become so popular is because of cost, not clean air...

[dcj13]

Originally Posted by Wanderer

I suspect that the main reason that FI has become so popular is because of cost, not clean air...

Cost, availability, reliability, performance, and convenience.

[allanoue]

Originally Posted by Wanderer

Is a correctly tuned carburated bike really more polluting than a fuel injected bike?

I suspect that the main reason that FI has become so popular is because of cost, not clean air...

FI is more expensive

https://www.revzilla.com/common-trea...fuel-injection

[Rifleman]

https://www.ninjette.org/forums/showthread.php?t=277104

[rgx107]

Originally Posted by Wanderer

Is a correctly tuned carburated bike really more polluting than a fuel injected bike?

The difference is huge and increasing for every generation. Emissions (CO, HC, NOx) from a properly tuned carb engine are measured in percent, in the best case a fraction of a percent. And the mixture is easily thrown off balance by changes in temperature, air pressure or fuel quality. FI will compensate for any of those changes, most of the time the emissions will be on ppm level.

[Ducati999]

Originally Posted by MLR

To be serious, Im talking to myself.

My current car is FI (2015 WRX STI), my old 50cc scooter was FI, for daily duties, fuel consumption (emissions) and all round smooth delivery of power I believe FI is the best.

BUT, when it comes to modifications, to take my car for example, I have replaced intake and exhaust parts, I have also increased boost pressure, BUT, it was the tuner and a aftermarket ECU which ensured it ran without lunching itself.

Now for the old FI 50cc scooter, I played with the airbox by removing a snorkle on it one day, it wouldnt run above idle due to the different fueling, I replaced the snorkel and it ran normal.

Now for carbs, all it takes is a couple of washers and some jets and generally away you go, yes it may take a while to find the correct jet sizes but I can do it.

Basically, if you dont mind playing around you can modify the hell out of your carby bike and have it running well with a screw driver and some parts.

Or, if FI, you need to look at playing with or replacing your ECU and logging data to review and adjust to ensure your modifications are not lossing power, or pay for dyno time and someone who knows what they are doing tuning your bike.

FWIW, Ive seen quite a few FI and carb bikes and cars that have had modifications to the exhaust and intakes and without correcting tuning they have lost power or lunched themselves.

@MLR,
Not trying to "call you out" or disagree with anything you said in your post I just want to add a little bit. Should I not represent my point well please do not take offense.
As @MLR stated," Just a few washers, a screw driver and a few jets". There is little more to "tuning" FI. Earlier my post described how easy it is to adjust fuel injection. There is no issue with making changes to an ECU. Just as easy as changing jets (less physical and more mental). People don't fear mechanical stuff as much but I have personally changed the fueling on several FI bikes and I aint that smart! Should any of you have a laptop, USB cable and a PC III or such add on fuel controller, you can easily download maps and the software is way more simple than Facebook! I think FI is significantly easier to make changes to than a carb. Yes carbs are simple but carbs don't give you "error codes" which tell you the MAP sensor is out of code. Compared to reading (or just removing) spark plugs, I will take the ECU. Carbs are a great solution but FI is way better. When you want to change the jetting on your carbs you need to read up on what part of the throttle opening each jet covers and with FI you learn how the "map" figures out how much fuel to add from all the sensors in the system. You can also usually change spark advance in the same map while you adjust fueling. Plus you don't have to remove the ECU to adjust settings. Like I tried to say in the beginning, I am not directing this at @MLR I am just using his post as an example and trying to get some people to not fear the electronic part of their fuel injection. Writing a FI code from "scratch" would be scary but changing a few values on a graph is so easy and you can leave the screwdriver in the box.

[Wanderer]

Originally Posted by Ducati999

@MLR,
Not trying to "call you out" or disagree with anything you said in your post I just want to add a little bit. Should I not represent my point well please do not take offense.
As @MLR stated," Just a few washers, a screw driver and a few jets". There is little more to "tuning" FI. Earlier my post described how easy it is to adjust fuel injection. There is no issue with making changes to an ECU. Just as easy as changing jets (less physical and more mental). People don't fear mechanical stuff as much but I have personally changed the fueling on several FI bikes and I aint that smart! Should any of you have a laptop, USB cable and a PC III or such add on fuel controller, you can easily download maps and the software is way more simple than Facebook! I think FI is significantly easier to make changes to than a carb. Yes carbs are simple but carbs don't give you "error codes" which tell you the MAP sensor is out of code. Compared to reading (or just removing) spark plugs, I will take the ECU. Carbs are a great solution but FI is way better. When you want to change the jetting on your carbs you need to read up on what part of the throttle opening each jet covers and with FI you learn how the "map" figures out how much fuel to add from all the sensors in the system. You can also usually change spark advance in the same map while you adjust fueling. Plus you don't have to remove the ECU to adjust settings. Like I tried to say in the beginning, I am not directing this at @MLR I am just using his post as an example and trying to get some people to not fear the electronic part of their fuel injection. Writing a FI code from "scratch" would be scary but changing a few values on a graph is so easy and you can leave the screwdriver in the box.

Not looking for a fight either, but how does people messing with the ECU profile affect the supposedly clean air benefits of FI? Both carbs and fi can be made clean and both can be made quite dirty.

Clean air is not so much about the technology, it's about the rider.

[allanoue]

Originally Posted by Wanderer

Not looking for a fight either, but how does people messing with the ECU profile affect the supposedly clean air benefits of FI? Both carbs and fi can be made clean and both can be made quite dirty.

Clean air is not so much about the technology, it's about the rider.

wrong

http://www.zeromotorcycles.com/

[Ducati999]

Originally Posted by Wanderer

Not looking for a fight either, but how does people messing with the ECU profile affect the supposedly clean air benefits of FI? Both carbs and fi can be made clean and both can be made quite dirty.

Clean air is not so much about the technology, it's about the rider.

Not sure if this was directed to me but you quoted my post and someone else.
Messing with the ECU can keep the emissions within the allowable spec if you set the air fuel ratio correctly. Should you want peak power then sometimes you go outside the proper A\f ratio but if you added a K&N filter and slip on then your bike is running lean and putting out too much Nitrogen particles. Adjusting the fueling for the increased air flow would allow more power and keep the emissions where they should be. Same if they did not set it up properly from the factory, adjustments can get the bike to run and idle better thru the entire rev range. You can also only richen the mixture under full throttle so you have good emissions unless you pin the throttle!

[Wanderer]

Originally Posted by Ducati999

Not sure if this was directed to me but you quoted my post and someone else.
Messing with the ECU can keep the emissions within the allowable spec if you set the air fuel ratio correctly. Should you want peak power then sometimes you go outside the proper A\f ratio but if you added a K&N filter and slip on then your bike is running lean and putting out too much Nitrogen particles. Adjusting the fueling for the increased air flow would allow more power and keep the emissions where they should be. Same if they did not set it up properly from the factory, adjustments can get the bike to run and idle better thru the entire rev range. You can also only richen the mixture under full throttle so you have good emissions unless you pin the throttle!

I guess my point is that whether we are talking about a carbureted engine or a fuel injected engine, the physics is pretty much the same. It's all about getting the correct mixture of air and fuel to the piston at the correct time.

Both technologies can be made to reduce the exhaust pollutants and both can be made to pollute when not tuned correctly or when extra performance is desired. The air/fuel adjustment screw on pregens is sealed from the factory and almost everyone breaks the seal and adjusts their bikes as they wish.

Quite a few of the people that preach about how "clean" fi is, also drive diesel trucks.

Again, in my humble opinion, it is all about how the rider uses and tunes their bikes that determines whether a bike is "clean" or not.

If people were really concerned about clean air, why do they have multiple vehicles in their garage?

I think that I will stop posting here to avoid a "cat fight" and let others speak, but most people that push "clean air" are hypocrites in my view.

[allanoue]

[Flying]

The emissions from carbs can be practically measured by the percentage of unburnt fuel mix down to 0.1%.

EFI emissions are measured in parts per million.

[dcj13]

Originally Posted by Wanderer

Not looking for a fight either, but how does people messing with the ECU profile affect the supposedly clean air benefits of FI? Both carbs and fi can be made clean and both can be made quite dirty.

Well said! Bravo!

[BoBO]

Carbs can get annoying when the jets clog up due to lack of use, but it's a simple setup. A little bit of B-12 and Fuel Stabilizer will fix that.

There was a time when I needed to go to work and the Ninja wouldn't run, so I had to take the car which was fuel injected no problems. Fuel injection is better in every way except when something goes bad, you have to find out what is wrong with the fuel delivery, locate the replacement part and fix it, but that almost never happens.

Ignition timing & fuel mapping are on a different level with fuel injection due to ecu & chip tuning capability. Fuel injection allows more accurate control of air/fuel ratio and adjust quick when elevations change, but enough of that.

I will always appreciate carburetors because of their simplicity and affordability. Right now my Mercedes needs a Mass Airflow Sensor, and I'm waiting for the UPS guy to knock on my door because no one had it in stock around my area. One bad MAS in 3 decades is not bad. My neighbors Camaro needs a new fuel pump as well. As you know carbs require little fuel pressure to run compared to EFI. Now he has to drop his fuel tank because there is no top opening for the tank. You can bypass all that nonsense with a carb motor unless it comes with a pump. Just take the carb out and clean the jets with a solvent for $7.99 lol.

It all comes down to what you're looking for in a bike. Right now, I need a bike that's cheap to maintain and capable of fast corner speeds. The Ninja 250 fits that description.

[BoBO]

Originally Posted by Wanderer

I guess my point is that whether we are talking about a carbureted engine or a fuel injected engine, the physics is pretty much the same. It's all about getting the correct mixture of air and fuel to the piston at the correct time.

Except that carburetors have fuel bowls, and when the fuel sits it evaporates which causes more pollution. That's why carburetors are slowly fading away. In addition, carburetors cannot adjust as quick a EFI units which causes more pollution and a higher carbon footprint. Because of the accurate and quicker control of the air/fuel ratio that the EFI provides, it should not be compared against a carburetor, and were talking about a factory tuned EFI not counting economy tune for hypermilling.

I doubt anyone here cares about clean air, but it's good to know that modern fuel delivery is on a different level when it comes to better performance, efficiency, consistency, and adaptability. Direct-Injection is another story.

[MLR]

Originally Posted by Ducati999

@MLR,
Not trying to "call you out" or disagree with anything you said in your post I just want to add a little bit. Should I not represent my point well please do not take offense.
As @MLR stated," Just a few washers, a screw driver and a few jets". There is little more to "tuning" FI. Earlier my post described how easy it is to adjust fuel injection. There is no issue with making changes to an ECU. Just as easy as changing jets (less physical and more mental). People don't fear mechanical stuff as much but I have personally changed the fueling on several FI bikes and I aint that smart! Should any of you have a laptop, USB cable and a PC III or such add on fuel controller, you can easily download maps and the software is way more simple than Facebook! I think FI is significantly easier to make changes to than a carb. Yes carbs are simple but carbs don't give you "error codes" which tell you the MAP sensor is out of code. Compared to reading (or just removing) spark plugs, I will take the ECU. Carbs are a great solution but FI is way better. When you want to change the jetting on your carbs you need to read up on what part of the throttle opening each jet covers and with FI you learn how the "map" figures out how much fuel to add from all the sensors in the system. You can also usually change spark advance in the same map while you adjust fueling. Plus you don't have to remove the ECU to adjust settings. Like I tried to say in the beginning, I am not directing this at @MLR I am just using his post as an example and trying to get some people to not fear the electronic part of their fuel injection. Writing a FI code from "scratch" would be scary but changing a few values on a graph is so easy and you can leave the screwdriver in the box.

No offense taken, everyone has opinions, hopefully from prior experience.

Im old and hate computers, I will never try to tune my WRX STI or anything else that has a ECU.

I purchased my first computer at 37 years of age, I can do basic EXCEL and that's it, I did once have a look at my fuel maps my old R33 Skyline which was running a LINK ECU, I instantly realized that I could easily destroy my motor because all the graphs and stuff had me stumped.

All my FI cars that have been modified have been tuned by a professional on a dyno, I am very particular about who tunes my car, if a shop has lots of shiny cars and bikes I keep walking, but, if it full of race cars that Ive seen perform I will book it in.

Also there is no way in hell I would ever use a off the shelf tune or something downloaded from the interwebs, you can have 2 identical motors but each will require different tuning, from my experience it's a cheap recipe for disaster.

As for carbs, from 1975 to 2000 everything I have owned has had carbs, I'm no expert but I can tune it good enough for myself, I even had a old LJ Torana with triple SU carbs, which were one of trickier cars I've had to tune but I was confident in doing it.

I guess what Im getting at is the best one is the one that you know and are confident in doing.

For me going for ultimate power, fuel economy, hippy green whales and rainbows I would say FI is the best but I will need someone to tune it, I've seen alot of stuff get lunched by people who think they know what they are doing when it comes to tuning a ECU.

But for a daily hack that I can do everything I need to with a couple of tools on the weekend, it's got to be carb.