So how bout you start over... tell us what exactly it is and isn't doing, and for each, under what conditions.
Also any chronology would help - a timeline of what it could and couldn't do when you bought it, and how that may have changed over time.
Also describe what you've tried and the results.
'01 660 Raptor, Burgard +2+1 arms, YFZ Shocks, LSR anti-vibe, CTR pipe, jetted, K&N
'01 Polaris Scrambler 400, K&N
'02 Honda 400ex, Big Gun pipe, jetted, K&N, Lonestar +2 A-arms, Lonestar anti-vibe
'04 Suzuki LTZ400
'16 RZR XP4 1000 Turbo