I ride with a guy with a SP500 efi and our speed, performance and gas mileage are about the same. I use my sp500 ice fishing on some very cold days up here in Northern Ontario Canada and it starts and runs fine.

I looked up the specs of a Sp 500 and it says its a 39mm throttle body,whats that mean does it still have a carb of some kind?

I know alot about fixing carbs but with EFI what do you do send it to a electronic technician? I just don,t get the EFI big deal and whats it all about.

Same with my trucks My old 1980 F-150 with a carberated 300 six runs the same as my 96 f-150 with a 300 six with EFI.

 

Tuning is way easier with EFI, driving on bad terrain (high angles) or riding wheelies is much easier with EFI, it won't starve out like a carb will. A throttle body is not a carb the 39mm is the size of the opening though.

 

efi is way better as far as starting, idling when cold and its stable vs carb. can be up and down. efi should be a little more power as well as the mixture and response is right there. the real only down side is that you do need to take it to a dealer w/ a computer to reset idle or computer functions. efi is the wave of the future of all atv sleds and what not i m guessing.

 

The EFI systems on these quads are very crude. They are just mapped system with a few sensors. Even with very few parts there are many problems.
Just punch in "EFI problems" in the search part of this forum and see what comes up.
When these things have problems they are very expensive problems. Injectors and pumps and wire connectors don't like dirt or water. OOPS, that's where these things run.
Someday the manufactures will get it right. That day is not here yet IMHO.

 

Another advantage to the EFI is you don't have to adjust the carb for altitude. I live at 295 ft ASL (above sea level) where i do some riding. But I do most of my riding at the Pismo Dunes (0-300 ASL) and in the Sierra Mts. the places i ride are any where between 5000' and 11500' ASL. So you can see that on any given weekend i can be from 0 to 12000' with no carb adjustment. i also like the fact that i have no choke to contend with.

 

Injectors and pumps and wire connectors don't like dirt or water. OOPS, that's where these things run.
Someday the manufactures will get it right. That day is not here yet IMHO.

>>>>>>>>>>>

I was told not to oil my air filter as excess oil can cause problems with an EFI sensor.

 

its true, but you'd have to douse your filter in oil and really let it drip before it messed with your EFI sensor. i ran a K&N that i cleaned regularly for 750 miles of my 800's life. no burp out of it

 

i jumped on the efi bandwagon pretty quickly and bought one and jumped off the wagon just as fast. I switched for an older 700 carb and am much happier. EFI so far does NOT start any easier than my carb. the only difference is efi you start and go where the carb likes some warming up. other thing, EFI does very poorly in bad terrain like swamps, deep mud and water. in 2 mths i visited the dealer 4 times for fried sensors and it leaves you there in the bush with nothing you can do. Performance: Here's my experience. I ride with a buddy who has same machine as I do but his is efi. Off the line, see you, the carb takes it hands down. mid range seems equal. top end he creeps by me. EFI needa a LOT of years of fine tuning on ATV's and carb is still proven, reliable and easy to work on rather than towe home and ride to the dealers. The only advantage to EFI i can see is for high altitude riding you dont need to rejet and you wont lose power. For me, that is of no advantage at all where I ride. Other than that, the better throttle response, more power and better mileage all seem like marketing as my experience in reality says nope, no more power, no better throttle response nothing. Just more to purchase and more headaches. Maybe if you ride dry hard packed trails only, you may be ok with efi.

 

I have a 2006 500 EFI. I could not be happier. I have had mine in water up past the seat on almost every ride I have done. I have not had a single problem from it. So really I think you will get different views no matter who you talk to. My buddy had his carb flooded in a middle of a huge mud hole, that was not fun, mind you if you know how to drive it wont flood. I had mine flashed before i picked it up from the dealer and I have not had it stall once. But if it came right down to it I wouldn't be upset if I had to settle for a carb but I would prefer a EFI.