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Big bear top end rebuild

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  #31  
Old 03-30-2014, 04:08 AM
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I will be putting it together in the next day or so. Now I know you said about 2 hours for break in period. So how long should the first ride be for? The full 2 hours or does it matter if I do it for 30 min at a time? Thanks
 
  #32  
Old 03-30-2014, 09:05 AM
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On first crank up,I just ran until warm and killed them until they cooled down.Doesn't matter on riding where you do it in intervals or not.Just no wide open throttle for couple hrs,but you can vary your speed. Hope this solves your oil problems.
 
  #33  
Old 04-04-2014, 01:00 PM
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I am installing my piston and rings today and wondering where to install the end gaps. I know they can't line up but any info would be appreciated. Thanks
 
  #34  
Old 04-04-2014, 04:39 PM
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Most manuals say to have rings staggered,end gaps not lined up with one another and end gaps away from intake and exhaust openings of the head.Letters/numbers on compression rings face upwards!
 
  #35  
Old 04-04-2014, 07:25 PM
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Ok thanks. I haven't heard of end gaps being away from the intake and exhaust ports. I've heard of them being away from the wrist pin. What is the purpose of this. Just curious
 
  #36  
Old 04-05-2014, 06:59 AM
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Strongest section of the rings toward the hardest friction points which is front and rear of the cylinder because of the motion of the rod.On a two stroke engine you don't have a choice because of the locating pins on the pistons that lined end gaps up with the intake port.. You don't have to line the two compression rings directly opposite each other,just a few degrees away on end gaps. I just lined both end gaps toward the rear,but one on the left side of the piston,the other on the right,both down from each side of the piston pin/circlip area. Just my way of installing them. Besides rings will move a little anyway over time,they don't stay rigid in one place.
 
  #37  
Old 04-11-2014, 12:19 AM
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Well I got the bike back together and it runs like a top with no smoking of any kind. The only problem that I have now is a slight backfiring on deceleration. I had this problem before the initial rebuild. I have no exhaust leaks of any kind. The carb has been jetted before I even bought the bike. I did go one size bigger on the pilot jet and that did seem to help some. Should I been adjusting the air mixture screw? Turn the screw in or out? Any guidance would be great. Thanks all
 
  #38  
Old 04-11-2014, 05:09 AM
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Drop the slide needle clip one position(raises the needle) if you can first and see if that takes care of the problem. Best way on fuel screw adjustment is while it's running and warmed up. Start at 2 turns out for a base setting.Look at the junkman's video to give you an idea how to do it. Good luck with the atv,hope the oil problem is finally solved.
 
  #39  
Old 04-22-2014, 06:40 AM
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Here is an update on the atv. I have about 35 miles on the new top end and its running great. No smoking, no backfiring, no hesitation. Thanks for all your help old Polaris tech.
 
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