I rebuilt the entire motor & replaced everything. New oil, spark plugs, antifreeze, water pump seal, all gaskets, balance shaft, jugs, pistons & seals, bearings, valve springs. Started up fine. Ran it here n there & put approx 5 miles on it around the house to see how it would do. Did fine just puttin around. Got it about 30-40 mph for about a minute, took it forever to build speed. Stopped shut it off, got it back up to maybe 35 if that, for about a minute then about another minute later it started sputtering almost like there was dirt in the gas or something then a couple seconds later it started smokin real bad from between the seats and on the passenger side above the oil filter. And it was makin an awful clanging sound. Very noticeable.
Have no clue what it is. No idea where to start. Plenty of oil in it after it started the smokin & clangin.

Utah RZR Rentals