I was thinking about getting a K&N air filter and was reading post and noticed several people talking about rejetting carbs after adding new K&N filters. Not being mechanical I was wondering if installing one on a 06 SP500 EFI would require adjusting anything since its fuel injected.

 

I would think it would adjust for it.
If you leave your airbox stock and use the lid,it should be fine.

 

Polaris efi machines will not adjust for more air flow. They use a set fuel map. However, adding just a k&n to your machine will be fine and will not need any adjustments. It will run fine

 

[img]i/expressions/face-icon-small-smile.gif[/img]We are running K&N filters in our 500 and 800 EFI'S...no problems...(2006& 2007)

 

My question is: should I use a prefilter with my K&N? Usually where I ride it's dusty as hell, but not this time of the year... Should I put the prefilter only when the conditions ask for it?

 

i run the stock prefilter with my k&n.

 

I'd go ahead and use an outerware with it.
Just a little added insurance.