I have another topic out there for other quad running lean. Since everyone has been so much help I need to ask another ?. I have an 08 sportsman 800 with k&n and an hsp exhaust. Do I need to buy a fuel controller? Will it help the performance? Will it run lean with out? Are they hard to adjust? I have not popped the plugs out and looked yet, but hoping someone has input on this! Thanks in advance.

 

The computer for the efi should compensate for the changes .

 

The factory computer will NOT adjust itself. It would need an 02 senser in the exhaust for that. It runs off a preset for intake air temp and barometric pressure to decide how much fuel for a certain throttle postion and rpm. I would check your plugs, but my 07 with a HSP pipe and can and a UNI air filter runs mint

 

I have a power commander usb on my 07 800 and with it alone I noticed a difference! I have a uni filter but have not installed it yet and I have a hsp pipe on the way it should be here today! The power commander is so easy to put on and adjust!

 

Thanks you for the input! I will check the plugs and see how she is runnin!