2012 sportsman EFI

ATV will start but acts like it has a misfire, loads up and smells rich of fuel.
if your genital you can clear it out and it will run good except it seems load on the top end like valve chatter.

I replaced plugs. found wear into the copper on the mass air sensor wires. repaired wires. cleaned and then replaced mass air sensor. checked valves but looks like they are not adjustable with hydraulic lifters.

pulled fuel tank and cleaned. inspected fuel pump and cleaned screen. looks like good fuel flow from injector line. put ATV back together. starts but misfires in reverse now.

lost on where to look next.

Thanks Marcus.