Hey diesel geek was correct . The computer on the dales are totally sealed and so is the whole fuel injection system. Not so with carburators. The whole electrical system is sealed also. There have been a few cases with seal integrity on the wiring but this is a quality control problem not a design flaw. You can totally submerge a dale including the computerand it will run as long you keep it from injesting water into the air filter. Some other threads show how easy Cannondales are to get water out a drowned engine.
The point about tuning is the whole reason I bought my dale. It can be retuned in seconds with the apropriate diagnostic tools and they also have a map selector kit which allows for retuning on the fly as you drive. Ive done it and its easy. The better car computer systems nowadays no longer require you to replace the prom chips and can be retuned with a laptop just like the Cannondale. I dont see how rockrider says that its harder to change a pipe because it took me 4 minutes to remap my Cannondale after installing a big gun exhaust and 2 of those were waiting for my laptop to boot up. How long does it take to rejet a carb correctly? From my experience its several hours with trial and error jetting and disassembly required.
I have been a ASE master diesel tech for the 6 years and have been working on caburated engines since the mid 80s and from my experience switching to fuel injection was a blessing. The biggest advantages are increased engine life better drivability and faster diagnostics. Nothing trashes engines like an incorrect air fuel ratio and thats where the self adjusting properties of EFI shine.
One of the best examples is last memorial day weekend up in northern wisconsin(Hurly) . My brother and his buddies are total 250r fanatics. It is sometimes got a little boring riding with them because almost every time we ride one of them is pulling over to change jets because "its not running right". Two of them siezed up on the trail (one was a total melt down and the other was able to continue after richening it up.
Im sure if those r's had a EFI that compensated for a lean or rich condition they wouldnt have had any trouble .
Dont get me wrong I dont think the dale EFI is perfect.It still needs a oxygen sensor feedback circuit but man does it give that motor some great low end and a screaming top end.
Diesel geek do you drive or wrench on diesels?
I think the reason some people dont like EFI is because its not as easy for the average person to understand how it works compared to a carb which makes repairing and diagnostics nearly immpossible. Thats what repair facilities are for or buddies like me.

 

jeez! as if aftermarket stuff fer atv's isnt expensive enough! wait till a guy puts some bad gas into one with an efi system. look out!!! whats the point with an efi? you typically have one cylinder and 1-2 carbs. thats alot simpler to deal with then an efi system. and the average joe can work on a carbed system with out spending tons of money on diagnostic equipment. nathan

 

There wouldn't be the elevation problems with EFI would there?

I was hooked when I bought my first car with EFI. (No more pumping the gas to start) Better gas mileage, better power.

 

Ever tried correctly jetting carbs or sincronizing carbs. Needles and pilots and float levels and diaphrams oh my.
Efi can tolerate bad gas up to a point because it can compesate for fuel quality and atomizes the fuel better any carb.
Do you think the new V force would get such horrble mileage (8 to 10 mpg)if it had EFI on it?
You can also let efi sit for long periods of time without worring about clogging the jets and leaking because the fuel in the system doesnt have exposure to the air so it doesnt oxidize and evaporate leaving that nasty brown goo to clogg it all up. I work on lots of wheelers and that is a very common problem. Ive thrown many a carb away with a clogged metering circuit that was unreparable.
Efi can also run at extreme angles and rough conditions which is also something no carb can do without special float devices.
For us older mechanics the biggest nightmare was the early eighties cars with electonic feedback carbs. They had all the problems with the carbs plus incorparated computer metering which was not very reliable. By the way the new Yamaha has electric sensors on the carburator.
When I was looking to buy a corvette I drove many of the older ones with carbs and when I test drove a 1985 with port injection and was a night and day difference in power. The engine was still the old small block chevy with just efi and man way better mileage and low end torque.
Buy the way I take pictures with a digital camera now which I can print out great pics instantly and email instead of writing letters. Dude its just new technology . You have to embrace it or live in the past. Its the difference between the Amish and Regular america. Thats why we fly on jets today instead of the piston engine aircraft. I can go on and on.
I apologize for rambling but I hope you get my drift.

 

I come from the motorcycle aspect, Honda has just started using fuel injection extensively on motorcycles over the past few years and the difference in the way the bikes run is stunning. The fuelies run much better under almost any condition, and vastly better under some conditions, like cold running, and decel, and on and off throttle transitions. Yet in terms of complexity, the fuelies are VASTLY more complicated. I mean, we're talkin connectors with 1mm or smaller pins, and sometimes 20+ terminals. How many times do you think you can reconnect these couplers without seeing some kind of connection problems? In terms of harness problems, the potential for a nightmare is there, and I have seen it. Not to mention the hostile environment atvs are subject to. Believe me, if there's a way for water to get in, these atv guys will find it. And what's waterproof on a new machine may not be after 5 years use. Anyway, I largely agree with what wistech wrote. But after 24 years of cleaning, synching, and setting carbs, I've come to be kind of fond of them. I

 

Nah - EFI's not as technical as it first seems. And it can be EASIER to diagnose than carb problems, once you get the hang of it.

Remember, the goal of carburetion (or fuel injection) is to put the most accurate mixture of fuel and air into the cylinder under all operating parameters - full throttle, puttering down the driveway, idling in the winter at 6000' elevation, etc. We all know that carbs do a pretty good job at this, but fail with differences in air *density* such that they need retuning... EFI is built to compensate for this automagically... read on...

There are two basic types of EFI - Speed Density and Mass Airflow. The difference is the way the air going into the engine is "metered" - Speed Density EFI systems use input from the Throttle position sensor and the Engine RPMs to determine how much fuel to add to the incoming air (think 2500 RPMs times the displacement, and you know how much air the engine is pumping). Mass Airflow EFI systems use a Mass Air Meter (or MAF) meter to measure the actual quanty of air coming into the engine.

In both of these systems, the information goes to the computer - then the computer makes a decision about how much fuel to put into the airstream just before it enters the cylinder. For example: In Mass Airflow systems, the computer will see an input from the MAF saying "2.5 volts" and it loooks up 2.5 volts on an internal "chart" (aka programming, or "maps") to see how much airflow 2.5 volts equals. The computer comes up with "200 cubic feet of air per minute" and then looks up in another table how much fuel should be mixed with 200 cfm of air - and it finds that 200cfm of air needs ".03 lbs. per hour" of fuel - so now the computer knows the quantity of fuel that needs to be mixed with this incoming air - and it signals the fuel injector with a tiny electrical pulse to open up for a certain period of time. The computer knows that the fuel pressure is, say, 40 PSI - so it looks up in yet another table how long it needs to open the injector nozzle to get .03 lbs./hr of fuel flow, and then it signals the injector to open for that period of time.

The whole process of "tuning" EFI systems involves changing the information in all the "tables" - for example, if you put a pipe on your cannondale, instead of rejetting the carb, you need to go into the chart that tells the computer how much fuel corresponds to given quantites of air. Now, that 200cfm of air going into the cylinder might need .029 lbs. per hour instead of .030.

Of course, if our imaginary quad's EFI system is "closed loop," (another new term!) you won't need to do anything to the tables - because Closed Loop systems use another sensor, the O2 (oxygen) sensor, in the exhaust pipe. The O2 sensor tells the computer how much oxygen is left in the exhaust after it has been burnt in the engine - and it uses this information to make adjustments to the tables. If the closed-loop EFI system on our imaginary ATV sees that there is less oxygen in the exhaust stream after we installed our new pipe, it automatically will "lean out" the mixture until the expected quantity of oxygen starts to appear in the exhaust stream. A lot easier than rejetting, no?

The beauty of computers is that all these "lookups" of information can happen incredibly fast! And the tables can be changed relatively easily.

Some EFI systems, especially aftermarket ones, use computer software to tune or configure the ECU / ECM (engine control unit or engine control module). Most EFI systems nowadays also incorporate control of spark timing (so it knows that at 2000rpms, and 200cfm of air, that the engine needs .029 lbs/hr of fuel and ALSO needs the timing advanced 8 degrees! See where this is going? The more detail you add - the more efficiently the EFI system will mix the air and fuel. Where EFI really shines is during "part throttle" or cruising. Since the engine is not under WOT or full load, you can get away with running a much leaner mixture - and therefor you get better fuel economy. It's difficult (but not impossible) to tune a carb to know that during part-throttle cruising, it's ok to let the mixture lean out to save fuel and keep emissions down.

Most EFI software makes it easier to tune than having to manually edit all the different tables/charts stored in the ECUs memory. For example, the "speedpro" system we use on high perf street/strip engines combine many of these tables into one called "Volumetric Efficiency." Basically, it's a spreadsheet full of cells that combine many tables into one, making it easier to tune the engine without having to edit 20 different tables individually...

Finally, diagnosing EFI problems is not that difficult. Almost all automotive-style sensors work off of +5 volts, and use 0 - 5 volts as their signal. So you can use a cheap Voltmeter (or VOM) from radio shack to see if the sensors are putting out the right voltages, and if that voltage is getting back to the computer. You can use a fuel pressure gauge to see if the fuel rail is pressurized to the right PSI... and most of the time, the onboard computer will even tell you if there are sensors whose voltages are not making sense or aren't getting into the computer - another col thing about computers, self-diagnosis!

And as was mentioned earlier, EFI won't gum up because the fuel isn't allowed to vaporize. It works upside-down or sideways, unlike a carb... and therefore is good!!

Sorry for the long post,
-dg

 

DG, you said a mouthful. Thanks, nice to see facts and useful info in this forum. Sounds like efi will eventually overtake carbs on quads, like they did 20 years ago on autos.

 

I don't diagree at all that EFI is superior to a carb in terms of making an engine run much more efficently. But, the system has no place on an ATV. I can see it used on street bikes as they arn't used in mud, snow, deep water crossings, silty rivers, and sure don't take the abuse of being rolled, hucked off jumps and slammed through whoops. EFI is a very complicated means of metering an engine's fuel/air requirements.

I have already watched EFI come and go to an extent in the snowmachine world. Arctic Cat is the only OEM offering EFI. There system does not require a battery. Still, guys run into a lot of problems when they mod their sleds. Perhaps AC's system is not as advanced as Cannondales, I don't know. I have seen lots of the older Polaris RXL's towed back to the rig because you couldn't fix them when they broke up on a glacier.

Like was mentioned before, you don't need all the diagnostic equipment to work on a machine with a carb. What do you think will happen to all those Cannondales as they become 2nd and 3rd hand machines? There is no dealer to support them, the original owners who were at least familier with EFI will be long gone leaving some poor sap trying to chase down sensor and electrical problems that he wouldn't have to deal with if it was carbed.

You have to remember the real reason EFI came about was not for performance but for emmissions. The EPA forced the auto manufacturers to clean up thier vehicles, EFI was the technology that allowed them to do it. Now it is trickling down to the recreational vehicle level where it does not belong. For instance, I've got an '84 Honda 200S that 99% of the time starts third pull no matter how long it has been sitting. We are talking a 19 year old ATV. Now, go into the future 19 years, will the Cannondale even be running? With the super common parts for the 200S carb I can rebuild it like new. Can the same be said for Cannondale or Gas Gas (I believe their ATV is EFI).

If you use sleds as an example (and I don't know how familier you are with them) you can take a look at the market and see that after the early 90's when EFI was quite popular the buyers rebelled and quit buying sleds with EFI becasue of the limitations for mods and the difficulty in working on them. Once the sled is out of warranty those trips to the dealer cost money. Trips you wouldn't have to make if the sled had carbs. There are far more older non-EFI Indy 500 sleds still running than there are EFI models.

Who knows, maybe the 2006 emmission regs will force EFI down everybodys throat and no one will have a choice. But looking at past history, EFI is not a good system to have on a recreational vehicle that is used for day to day play and work. On a racing model, sure. Those owners are willing to invest the time and expense to keep the machine running. The average Joe is not.

 

EFI is used in outboards. Can't get much more wet than that.[img]i/expressions/face-icon-small-smile.gif[/img]

 

I'm very familiar with sledding - my family used to live in northern IN and at least twice a year we'd go up into MIchigan with our sleds in tow. We were all Yamaha back then - everything from a little 250cc sled on up to a couple Exciters. My favorite was the 480 Phazer.

The fuel injection you refer to in sleds is DIRECT INJECTION - not indirect, as is the case with the EFI used in four strokes. I did a little more research and found that the Ficht Injection fiasco was the same for snowmobiles as it was for outboards - BAD NEWS.

As far as average joe tuning, coming from a carb background and having recently learned a lot about EFI - I'll take EFI *ANY DAY* over carburetion when it comes to troubleshooting - I believe I'm qualified to make this statement. 90% of the system can be tested with a VOM and a fuel gauge! Not sure where you get your ideas, but YES Fuel Injection can be used upside down, under water (so long as the intake air is dry), and it WON'T gum up like a carb after sitting because the fuel cannot evaporate out of anything excpt maybe the fuel tank itself. Check into aerobatic aircraft and the Fuel Injection mods they require for sustained inverted flight...

Look at the 5.0 mustang. Lots of guys were whining about not being able to mod Fuel Injected cars, and that all turned out to be old lamers crying for no reason - it's one of the most popular cars with the aftermarket.

Technology happens - get used to it because it's here to stay...

I really want to get a Canondale just to mess with the EFI. THe support on their boards is awesome - I would NOT be afraid of not having a dealer for one...