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  1. #1

    How Bad is a High Compression (180) on a 4 TEC engine

    I'm thinking of buying a 2003 Seadoo Sportster 4 TEC and it looks to be in good shape, but when I had a pre-buy inspection done, the compressions came out 160, 160, 180! The mechanics were concerned about the 180. What's the problem and how bad could this be?


  2. #2
    Water4fire's Avatar
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    I believe the N/A motors should be at 195lbs.? So 160 would be low. Also a 10% seperation is OK. Anymore I dig deeper.
    SO 10% of 180 is 18psi. Your at 20psi. difference from the other cylinders. Over 10% and nowhere near the 195lbs I believe they are supposed to be.

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    shrabber's Avatar
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    You will be fine you may just have what we call a happy compression gauge

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    Water4fire's Avatar
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    Quote Originally Posted by shrabber View Post
    You will be fine you may just have what we call a happy compression gauge
    Do you know the stock N/A numbers? Im a little hazzy this morning.

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    Duke's Avatar
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    Quote Originally Posted by Tomenyt View Post
    I'm thinking of buying a 2003 Seadoo Sportster 4 TEC and it looks to be in good shape, but when I had a pre-buy inspection done, the compressions came out 160, 160, 180! The mechanics were concerned about the 180. What's the problem and how bad could this be?
    Was the motor cold, hot? 180 would be OK for an NA motor but 160 seems low.

  7. #6
    ndarimont's Avatar
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    Also how long has the engine been sitting? Try doing a wet compression test. Put a bit of oil in each cylinder. If the compression comes up and the engine has been sitting for a bit then you should be fine. If the boat has been run recently and the compression is still that low but comes up with a wet test then you have rings and cylinder issues

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    imp0ster's Avatar
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    leak down test the biotch. Could be a leaky valve, ring or gasket. Blow by is no good. I'd never touch anything that bleeds compression.

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