Hey guys I recently found out my head gasket failed so I took the block off to change it and found this in the sleeve. Not sure if I should put it back together like this with the new gasket

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The pictures make it look worse. It is just the thin surface layer. The casting seems fine.

 

I would fix it right. That is only going to get worse and cause issues down the road. You are most of the way to having the jug off anyway. Get that cleaned up and some new pistons, rings, and gaskets. Check the crank while you are at it. Then she will be like new

 

Whether it's a 700 or 800, either the cylinder(s) have to be replated or purchase a new or used cylinder. The nikasil coating has flaked off.Cant be bored unless you install aftermarket cast iron cylinder liners and aftermarket pistons for this IF available. Cylinder's around $400,probably close to what the replating from LA Sleeve would cost,but you can call them or a couple other places and see exactly.Here's US Chromes' pricing.http://www.usnicom.com/plating/pricing

 

I am going to try and get used cylinders.

Polaris Sportsman 700 Twin ATV 4x4 Cylinder 80 06mm 02 2002 900 | eBay


I don't want to get new pistons if I don't have to.

 

Cheaper than having the cylinders replated or a new cylinder assy. Hopefully the used cylinder is in good condition.Be sure to check the piston to cylinder clearance when you get the used set in. Hopefully it will be within specs. Good luck,keep us posted.

 

Will do guys. Thanks.

 

Got my cylinder jugs. Now just need rings and lower gasket.

Polaris apparently doesn't offer the rings alone for oem pistons. I'm wondering if anybody knows if namura rings work with stock pistons?

I'll be reusing the pistons in the machine now.

 

Don't use rings from another piston as rings are made for each specific piston! All it will do is possibly destroy another cylinder.Apparently Partszilla has them even if Polaris doesn't show them on the breakdown.2202127 KIT-PISTON RINGS 80MM Spam wordSpam wordSpam word Spam wordSpam wordSpam word Spam wordSpam wordSpam word Spam wordSpam wordSpam word $31.91 Along with 3 places on ebay. http://www.ebay.com/sch/i.html?_nkw=...182&mfe=search
P.S.Polaris parts list doesn't show separate rings for the 2002 model 700,but do on 2003 model and up..

 

Thanks old polaris tech. You're the man.

Does the polaris ring kit come with rings for both pistons?

Also do you recommend getting new pistons or is reusing the old ones reasonable

 

Sorry,priced per piston. You need two sets. Best thing is to mic the piston to the bottom of the cylinder. Or any easy way is to insert the piston into the bottom of the cylinder,holding the piston skirt flush with the bottom of the cylinder liner. Use feeler gauges on the opposite side of the piston between it and the cylinder. Engine specs shows a tight fit. .0015 If a .002 or over feeler blade can slide in easily,I'd replace the piston. You don't want to do this job twice..