2008 sportsman 700 efi backfire through intake

So I just picked up a super clean 08 sportsman 700 under the impression it just needed a sensor, the previous owner replaced the t-bap sensor and harness with no luck. ATVs starts right up idles fairly well but when you give it the gas it wants to start popping,sputtering and just sounds aweful,also smells extremely rich to the point it burns your eyes, I checked all wire connections,pulled on wires nothing loose,cracked or rubbed through. I’m at a loss here any input would be greatly appreciated!!

2005 Sportsman Tires

Looking for good set of tires with decent amount of tread left.. Prefer stock size:

F: 26x8-12
R: 26x11-12

It the tires comes with rims then I will consider if price (including shipping) is reasonable.

2005 Sportsman Tires

Looking for good set of tires with decent amount of tread left.. Prefer stock size:

F: 26x8-12
R: 26x11-12

It the tires comes with rims then I will consider if price (including shipping) is reasonable.

Sound system for ’18 Sportsman 570 SP

My daughter in-law has an '18 570 SP and wants a sound tube/system for Christmas.

Any recommendations?

Main needs are Bluetooth capable, sound quality/volume loud enough to be heard while riding and most importantly.....ease of installation (as I will most likely be the installer :grin )

I'd appreciate any recommendations!!