Polaris 500 HO top end replacement(400kms!?)


Hey guys,

Just got my new 500 HO a few months back and after a ride the other day there was major banging from the top end. Brought it to the dealer and they had a listen and said its coming from the top end. The mechanics hauled the engine out and had a look in and said that there was major scoring on the intake side of the cylinder and the piston was damaged causing "piston slap." The mechanics said they have never seen anything like this on a brand new quad. There is 400kms on my bike. The bike has never been drowned in water or any major incidents on it. Its basically lady driven. My 500 is under warranty for the fix but im trying to pin point what exactly when wrong to cause this. Upon further inspection of the bike, there was oil pooled up in the air box that mechanic said it could have been sucked up there from the bike being rolled over or being on a steep incline for too long. Which it never has.

Ive been reading around and people were saying that a faulty oil pump could be a issue. Is there any way to prove this? Or to test that in fact that it is broken. Is there any other thing that could cause a top end to go on a new quad?! I'm boggled here. I'm worried that it will happened again after the dealer fixes my problem and I'll have to pay out of my own pocket. Thanks in advance!

The scoring on the intake side makes me thing the engine sucked something in and the debris rode around in there until it caused enough damage to start making a noise. Could have been something from when they manufactured the engine. Have you replaced the air filter before? I think a faulty oil pump would have caused more damage. My scrambler used to put oil in the intake box all the time. The crankcase and something else is vented to the box. It wouldn't take much of an incline to do it. It did it if the oil was slightly over full also. I disconnected the lines from the box and added valve cover breathers to them and zip tied them out of the way.

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