2009-2023 TRX420FA Rancher AT 420cc. 2009-2014 TRX420FPA Rancher AT 4x4 w/ Power Steering 420cc. Factory Racing Parts SAE 10W-40 Full Synthetic 4 Quart Oil Change Kit. Our 10W-40 Powersports Engine Oil is engineered specifically for 4-stroke motorcycle engines and transmissions.