Polaris Sportsman Ace 570 Rebuild - Part 2 - Assembly - New top end

If you saw my last video, you would have seen that "Dwight", our 2018 Polaris Sportsman Ace chugged some mud, essentially ruining the top end. We had a clogged throttle body, heavy scoring on the cylinder walls, and damaged piston rings. All the parts are in and today we are going to begin the assembly on the new top end!

Fortunately the top end of the 570 can be done with it still on the frame. If you need to do the bottom end, you'll need to pull the engine and split the case. Had it been run any longer, it could have damaged the rod bearings which would have required a complete tear down. That is why it is essential to shut off the engine at the first sign of trouble, especially when it is in the mud!

After tearing down this engine, I am glad that I went with a new top end. I am sure that I could have cleaned out the throttle body and it would have operated, but it would have been down on compression and burned oil. I also may have been able to get away with honing the cylinder and just replacing the rings, but after looking at the prices it just made more financial sense to me to replace the entire top end. It was roughly $400 for all the parts, which were in stock and I had them in 3 days.

Hopefully you never find yourself in this situation, but if you do this video should help. Everything shown here is per the service manual. This video is for entertainment purposes only, and no part of it should be attempted. Only licensed repair shops or your local dealership should make any repairs on your machine. Working on a machine yourself may void your warranty.