compression test

Discussion in 'Sportster Models' started by goofysniper, Apr 11, 2009.

  1. goofysniper

    goofysniper Member

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    I just did a compression test then I read you have to have the throttle wide open when doing it which I did not. I got a reading of 120 psi in both cylinders but is it inaccurate if the throttle was closed? Do I need to do it again? I also checked the plugs because I recently installed a screaming eagle carb and air cleaner and was getting a small pop out of the carb when I would blip the throttle a bit so I turned the screw on the bottom out about 1 turn. The plugs were pretty white. It also has S/E pipes. Did I do the right thing or at least close? Thanks in advance. James
     
  2. glider

    glider Veteran Member

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  3. goofysniper

    goofysniper Member

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    Does that sound like a lean problem to you though? Id rather go a little richer than leaner.
     
  4. glider

    glider Veteran Member

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    Popping back is usually an indication of a lean condition. Possibility you need to rejet the carb for your bike.

    As far as setting the PROPER mixture, read through the self help area and you can learn the proper way to do that too. It's not just a matter of opening the idle mixture screw.

    More than likely the plugs will remain white, the color of the plugs now with out the leaded fuels will be white and the only exception is the additive packages in the fuel that will give them color but is not an indication of the proper mixture.

     
  5. goofysniper

    goofysniper Member

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    Thank you very much. I just turned it out a little so it wasnt running to lean. It needs to go to the dealer anyway so maybe they can tell exactly what it needs. Runs real well otherwise. now I just gotta put my streetbob bars on.
     
  6. glider

    glider Veteran Member

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  7. goofysniper

    goofysniper Member

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    Not off hand. Its a 44mm big bore CV screaming eagle I got from the dealer. Cant locate the papers for it. Re-did compression test, 150 psi in both cylinders with 10500 miles on it.
     
  8. glider

    glider Veteran Member

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    150 is more like it.

    The 44 is a BIG carb for that sportster. Why did you go so big? It's not an advantage to have a carb that is too big, the flow isn't as good as the smaller carb.

    10500 miles on a 97 sporty?
     
  9. goofysniper

    goofysniper Member

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    I thought the dealer would know more about what carb i needed. I needed a new one and they said that one would be fine. I wasnt lookin for more power or anything, just a reliable carb for it. Didnt know the 44 was so much bigger. Is 10500 alot of miles?

    By the way, Im in love with the color of your bike!!!
     
    Last edited by a moderator: Apr 11, 2009
  10. glider

    glider Veteran Member

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    Not for a 97 but the 44 is big for that motor. It's usually for a motor with more output. Bigger isn't always better in all situations when it comes to carbs.