So I blew my engine in my 04' Polaris Predator 500. I bought a bottom end from someone and it seems to be fully functional. I took it to someone to see what else I needed and he said I should get a Big Bore kit in order to finish my motor. Is this all I need to put my engine back together? A big bore kit? If so which one do you all suggest.

 

Several of them out there. Several on ebay on big bore kits,plus here's another place.Aaen Performance : Polaris Predator

 

So all i would need to complete my motor would be a big bore kit? Any type? I see a lot of JE ones on ebay and Wisco i believe the brand is. They come with a piston, rings, and gasket. Should i worry about getting a sleeve also?

 

Cylinder sleeve needs to be replaced(machine shops can do that for you) plus most good kits like Wiseco come with over size sleeves. Just my two cents I'd trust them more than any other kit.http://www.ebay.com/itm/POLARIS-PREDATOR-500-WISECO-BIG-BORE-KIT-558CC-12-5-1-/361145195391?pt=Motors_ATV_Parts_Accessories&hash=item5415ee5b7f&vxp=mtr

 

Ok, thanks a lot for your help!

 

Is the valve train still sound? How did it blow? If you just need a piston, then going with a BBK is generally a good upgrade for not much more cash.

 

I have no idea how it blew to be honest. I was downshifting after racing a few friends and when I got to second gear I heard a loud pop. Looked down and a huge hole had been blown out the rear end of the motor. It also cracked my piston when it happened.

 

You may have gotten lucky, but I would check that top end closely to make sure you didn't bend a valve or anything. Also a good time for a new timing chain/tensioner.