I have a 4hp yamaha 4 stroke on mine and it does just fine. Really I have never opened it up as I dont need speed just the ability to move easily. I also have a 55ft lb trolling motor and I have yet to try it on the argo, it did VERY well on my max iv and it was not nearly as well mounted.
Jason
2015 Argo frontier EFI Camo. 4000lb vortex winch with synthetic rope. 3.3 trans.
~1998 Max IV (SN 14428) on 26" TRU Power tires, winch with synthetic rope, rear seat moved back 5 inches, flip top rear seat with storage underneath, 55 lb thrust trolling motor, #24 marine Battery and a bilge pump just in case.-sold