Okay i got the ATV ripped down the piston was missing both sides of the skirt so i split the case and cleaned everything now i'm ready for a new top end.

Denn kirk has a new different bore sizes to pick from under Xplorer 400 can someone help me pick the one that would be OEM bore?

they have
84.5MM
85MM
83MM
83.5MM

I've rebuilt dirt bikes make times and they always have a stock bore piston to pick from but not for this I guess. can anyone help me?

 

Your dirt bikes were probably chrome bore(plated cylinders) if you only had stock size available. 400 boreable cylinder and you really need to measure cylinder clearance at bottom of cylinder to order correct piston size that will clean up bore with out ordering one too large that will cause you to loose extra rebores. Most shops will measure for you if you bring cylinder in. I do it often!

 

Thanks for the Advice I got it honed everything looks good now.
The ATV is all back together tonight i'm going to start breaking it in. I've really missed the machine looking forward to riding it again.
Replaced the CV bearings too which was more of a pain than i thought but least it's done now. the Belt is down to it's 1-1/8th so thats Min the book says so i guess i should invest in a new belt too.

 

Do you what plan get new one piston, Dont buy a use polaris piston can cause easy broken! Other better use wiseco piston or other coat skin cover on piston. Your stock size piston? 83mm piston stock get cut bore wall cycling go to piston 83.5mm

 

<div class="FTQUOTE"><begin quote>Originally posted by: xplorer 400 4x4 with modifition

Do you what plan get new one piston, Dont buy a use polaris piston can cause easy broken! Other better use wiseco piston or other coat skin cover on piston. Your stock size piston? 83mm piston stock get cut bore wall cycling go to piston 83.5mm</end quote></div>

umm.....do what?