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Need help with timing on a 98 sportsman 500

  #31  
Old 08-29-2016, 04:55 PM
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Originally Posted by 98Sportsman500
Random thought any other test like compression that will give any confirmation of cam probably not as it's an exhaust lobe issue huh
55-95 psi compression on average because of the decompression device. Some machines may show a little higher.
 
  #32  
Old 08-29-2016, 05:13 PM
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Trying to think about it in terms of the cam compression will test good even though exhaust lobe is worn is that accurate
 
  #33  
Old 08-30-2016, 12:45 AM
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a bad cam would have no effect on a compression check
 
  #34  
Old 08-30-2016, 07:35 AM
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Correct.. You can have a flattened lobe and still show within range because of the decompression device.
 
  #35  
Old 08-30-2016, 09:29 AM
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That's what I thought I am gonna bite the bullet and pull the cam and be done with this project lol details to follow
 
  #36  
Old 08-30-2016, 11:52 AM
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Originally Posted by 98Sportsman500
That's what I thought I am gonna bite the bullet and pull the cam and be done with this project lol details to follow
You don't have to pull it.. Just a visual check is sometimes all that's needed if it's ground down bad enough. If in doubt measure the lobes and look at the rocker arm for scarring. Here's a bad one up against a new one.
 
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  #37  
Old 08-30-2016, 01:38 PM
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Sorry yah I meant pull the cam not the motor but I guess I could pull the rockers first and rotate the engine a couple time and see if I can ID the lobe or lack of a love
 
  #38  
Old 08-30-2016, 03:40 PM
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That's what I meant too.. Just examine the cam.If the cam needs to be replaced you can replace it with the engine still in the frame.
 
  #39  
Old 08-30-2016, 03:54 PM
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Absolutely thanks for all your excellent advice getting to this point
 
  #40  
Old 10-02-2016, 04:26 PM
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Well OPT so just went ahead bit the bullet and finally put a new cam in it to no avail still idles like a dream but when I give it throttle it bogs out with no gain in rpm as a matter of fact it almost stalls
 

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