It would seem the biggest concern that people have is with the ECU itself, and the durability of it. I'd just like to point out that I have an ECU in my For F250 truck, I take it on the dunes through the mud and everywhere in between. Snowmobiles have used ECUs for nearly 4 years, which is one of the most demanding environments around, -30 degrees, and those take a huge pounding depending on the type of snow they ride in. ECUs are in water craft as well - I dont even need to mention that environment. And as far as quads, Check out the Utes that are already using it, the Polaris 800 and Bombardier 800 Outlander. I have seen no ECU failures on those. Lets face it, ECU came out in the automobile industry in the late 70's and early 80's. They've had 20 years to harden them and perfect thier durability. And if you think you dont have electronics on your quad now, consider all the stock CDI's and rectifiers that have been put on quads for the last several years. Some of the aftermarket CDI's out there are quite amazing. Consider the Vortex CDI, which holds up to 10 ignition timing curves with the ability to switch between two of them on the fly. 135boom is correct, there are some very cheap CDI's out there with questionable history, but you get what you pay for. Further, the ECUs in these quad are of open loop origin. They dont depend on an oxygen sensor to make decisions. The main problem with the closed loop system, that depend on an oxygen sensor and when that sensor fails, it tells the ECU incorrect information which can lead to a lean condition and engine damage. Therefore, I feel pretty strongly that the ECU's on atv's are not only durable, but accurate as well. The only thing I'd like to add is the aftermarket EFI controller. I would suggest looking for one that is waterproof, and one thats easy to manipulate the EFI flow. If you get one, you might as well get one with all of the options avaiable. Some of them are so advanced that they can be tuned to work with a turbo, supercharger, and Nitrous along with a ton of other high flow mods. Another nice feature is the ability to adjust your injectors right there where you ride, with no need to download another program and upload it onto the controller.

 

I don't know if this was a typo or not but this info is incorrect. A closed loop relies on sensors like O2, temp, ect, ect. Open loop defalts to a set on board hard map.
Closed loop systems are nice because it can adjust to mods, within reason. Closed loop is bad because sensors are not that hardened.

Another myth is that you can get more power out of EFI. The truth is, a perfectly tuned carb will put out more power; not much, but it will beat EFI for total power. Also; this is WOT total power, not different RPM ranges.

On another potential problem with EFI that no one mentioned is logging and warranty issues. These things will log all info in the puter. If you break your quad and bring it in for repair the first thing the tech is going to do is pull all of the logged info out of the puter. Some shops are going to have a problem if they see 90% (or whatever) WOT times logged in the puter. Just another way to beat you out of the warranty if you ask me.

 

Correct on the typo. Thanks!

 

[quote]
Originally posted by: Doctorturbo
This is a problem with all aftermarket parts on a quad. Yamaha has a 90 Day warranty, so, what a lot of people do is wait until the warranty is over than make the mods. However, you are correct that the memory of the ECU will keep some information in the buffer. However, just like removing an aftermarket exhaust, the memory in an ECU can be reset. Its simply a matter of disconnecting the power on most of them. I dont have any direct experience to know if the ECU on the 700R can be reset in this way, but that how I've reset other vehicles.

 

Some very good points

 

I think if you were to look in the threads all over the internet, you'd see an even debate about the the power difference between EFI and carb. I dont think there is real data to support one is better than the other on the power front, other than simple opinions. My opinion, if the a/f ratio is correct, there should be no power difference as long as the other variables are the same.

 

Ive had to change out the ECU on every fuel injected vehicle I have owned atleast once. I dont even want to get started on how many sensors I have changed. It gets expensive, thats all I am saying. When electrical things go bad it sucks, it especially sucks when it starts to go bad in an expensive and complex system like EFI. I can rebuild my carb sitting on the side of the road, I cant really say that for my fuel injection system.

 

Well, I suppose thats possble. But I've owned 5 fuel injected vehicles, and one with over 215,000 miles - I've never had to replace an ECU on any of them. As far as sensors, thats a moot point since these ATVs dont used A/F ratio sensors. If you talk to most auto mechanics, Any ECU built after 1990 are nearly bullet proof. Further, I've never heard of an ECU going out on a sled, which is a better comparison.

 

Actually with at least the EFI on my Raptor...If you just disconnect the battery for a minute it will delete the stored information.

 

Forgot to mention that the Raptor has a "tip sensor" in it as well. The ECU stores a code if the ATV has ever been upside down flipped etc. This is grounds for warranty removal. But again if you disconnect the battery it will delete the code.