if you're talking about 2 stroke,i prefer a perfect jetted keihin carbed quad,with good porting nothing
is smoother,but the emissions laws need EFI and such goodies to keep pollution level down,but id doesn't
mean it make more power,just ask to 01 raptor owner with 2 carbs,those thing run great if jetted properly.

 

It will take over just like it did with cars.

Just like with cars, eventually all quads will have computer diagnostics and R&R will be the norm for techs. All the guess work will be done in real time with virtual conditions.

EFI and radial tires will take over ATVs just like they took over automotive.

The argument will always exist as to which is better for what. But the fact remains that the ease of use and overall peformance (on both fronts) will eventually win out in the long run. "Dial In" torque/HP curves are going to really change off-road riding and racing. EFI also takes up less space and weight than a carb does, and you can mount them almost in any configuration making design profiles more open too.

Wait a few years and you will see EVERY Motocross/Supercross, ATV and 2-wheel alike will be running electric starters. I know for a fact that several manufaturers are working on small and light starter/battery packs for Motocross Bikes for use by the top guys. These 4-strokes are so hard to start when they are warm. If you put in a one or two shot starter pack on an MX bike, a simple stall won't cost you 12 positions like it does now.

For all intents and purposes a "stall" is what cost Bubba Stewart the AMA Supercross title to RC. Had Bubba been able to get his bike started sooner after that little fall in the race where Ricky Carmichael DNF'ed with a broken shock he would have won the title. But it took Bubba about 25 kicks to start the big green 450 and it killed his points off almost as far as RC's DNF did. The same could be said for Honda rider Josh Grant, who had a stalling episode that cost him many points in the Lites Division.

Sometimes progress is only for the sake of progress, but sometimes it is for the better.

 

I take exception with some of your statements.

"Just like with cars, eventually all quads will have computer diagnostics and R&R will be the norm for techs. All the guess work will be done in real time with virtual conditions. "
You just don't hook a car up to a tech 2 and it tells you what part to replace. Let me put it to you this way. What car is easier to diagnose with a fuel problem. A 69 Camero with a small block in it or a 2003 Camero with a ZZ6 in it? For the 69 its going to be the tank, the pump or the carb. I would have to stay up for 48 hours to type what could be wrong with the ZZ6.

"Dial In" torque/HP curves are going to really change off-road riding and racing. "
How is this done by just changing to EFI?

"EFI also takes up less space and weight than a carb does "
Say what??????? !!!!!!!!!!!!!!!
The wireing harness alone for my Accel system almost weighs as much as my carb does. Then you have an air box which almost weighs as much as a carb. (same as a carb without the float bowls). Then you have all the sensors that go with the system. And last but not least you have the puter, which is not light its self.

 

Doc

I know I was being short in details there. But I worked for Ford for many years and a lot of the guess work of old has been weeded out.

Of course I understand a "check engine" light can return many different codes that can range from an O2 sensor to MAP sensor to a knock sensor.

And on the 69 Camaro in order to get the exact diagnosis of which it might be you need to do even more tests. You're not going to drop the tank if it's a clogged fuel filter upstream. The diagnostics involved with tracking down a fuel delivery problem is the same in a new car. If fuel is not being delivered in a new car it's still probably the pump/sender unit. A sensor is not going to stop fuel from being sent in general.

You have an airbox with a carb too, and hoses and clamps and etc.... Besides the new carbs are computer controlled already so they have all the same harness already there. Essentially you are swapping out a carb for an injector and throttle body. Perhaps overall there is not significant weight savings, I probably worded that wrong. My z400 has a TPS on it already, and electronic ignition, and all kinds of harness for various sensors. If the carb was swapped out for EFI it would not be heavier. The new carb systems are already 2/3 of the way there.

What I meant by this was the spacing configuration. Manufaturers can place an EFI system and electronics in a lot more vaired location configuration. It does not have to sit above the engine in the frame which will allow for engines to be placed in varied positions to possibly raise ground clearence or lower the engine.

Well with EFI there is no jetting or adjustments required. The techs will be able to choose torque/HP curves right there in real time. Right now your jetting limits the amount of configuration you can benefit from. You can advance or retard your timing, but the fuel flow stays the same. Eventually the average trail rider will be able to dial in which setting they want. Whether you are in the dunes and need top-end of you are in the slop and want torque at lower RPMs, you will eventually be able to choose.

Of course I was speaking about the ultimate end, the future and benefits of EFI. Just like in your car, you will be able to buy chips that reconfig everything through your computer.

At this point it becomes an argument of semantics. People will always feel one is better than the other and if all the benefits were not apparent they would have never switched over in cars either. Overall efficiancy is better with EFI, simple as that. Of course there are negatives about everything.

 

I think your very confused on what an EFI can do. An EFI just sets the amount of fuel an engine see's at any given time. CFM for CFM a perfectly jetted carb will beat an EFI when it come to horsepower.
You can not set torque or horsepower with fuel flow. I wish it was that simple. You can on a diesel, but not on a gas engine. To get the most power, you have to set fuel flow at around 12.5 to 1 fuel to air ratio. Any more fuel, and you will loose power, and less and you will loose power. To get the best economy, you need to set the ratio at 14.7; stoichiometric.
The only place EFI really shines is with extreem temperature changes or extreem altitude changes. Other than that, it's just a VERY accurate carb.

 

Why does the EFI Suzuki 450 have (need) a choke? Im confused

 

Doc

Well I as I said I'm talking a benefit in overall tuning. Incresed fuel flow can be taken advantage of with electronics and ignition timing. EFI can be set to increase or decrease fuel flow with the computer. When you put an advanced timing chip into your car the computer will increase the length of fuel stage that is shot into the engine. A carb cannot be tweaked in that way.

I never argued that a carb is bad or makes inferior power. You are 100% right! A perfectly tuned carb system is excellent, especially the new systems with TPS and electronics.

 

I don't know the quad or the engine but if I had to take a wild guess I'd say:
EFI cars have a lot of sensors. These sensors give the puter feed back to tell the total management system what to do. The EFI on quads are not like that on modern cars. They are very crude.
To give the puter feed back on a car, you need a water temp sensor. Some even have air intake sensors and more. These sensors will tell the puter to tell the injector that it is cold out and to give the engine more fuel. When the engine is cold it goes into "open loop" which just means the puter does not listen to the sensors and it just deflaults to a pre-written program.
When all warmed up the O2 sensor and many more will tell the puter that the injector is giving the engine too much fuel and to cut back. When all sensors are in the game that is called "closed loop".

I know of no quad (yet) that has an O2 sensor. (there may be but I don't know of one) Just a guess, but maybe the Suzuki 450 does not have some of these sensors because they are trying to cut down on weight? Just simpler to add an enrichener valve?
Maybe they are worried about reliability? Even on relatively clean and vibration free roads, car sensors go out from time to time. Leading a race would not be the time to have a sensor go out.

The way some of the people on this board use their quads as boats, they are going to be in for a shock at the cost of a fix if silt and water ever gets into the fuel system. It won't be cheap!!!!!

 

It won't be long before quads have O2 sensors and cats. I would also assume that at that point, they will also get a fuel injection system that is more modern than the ones that went into the first diesel motors.

 

02's and cats?

Geez I sure hope not. I think they should just stop at the EFI system and call it a day for the next 25 years.