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  1. #1
    steven mace's Avatar
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    Question Why do 4 tec blocks have thrust bearing failures?

    Ok guys, who is in the know? So many 4 tec blocks have the damaged thrust bearing area in the block. What's the go? They are all over ebay.. Engine sitting to far back and the jet shaft pushing the crank into the thrust area? Engine mounts getting soft?
    They are a crap design of the thrust area on the 4 tec. Only half a thrust bearing? Why not run a full one like a car engine..

    Let me know your thoughts. Don't want it happening again to my ski.


  2. #2
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    Lost mine to a loose prop, pushed the driveshaft back and there ya go.

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  4. #3
    Eastside Powersports Slow 91's Avatar
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    pretty much the only thing that can cause a thrust failure is force on the crankshaft. I have seen it mostly due to props coming loose, broken motor mount. I also have seen people replacing all motor mounts, getting the alignment correct but not realizing the motor is too far back causing constant pressure from the driveshaft.

  5. #4
    steven mace's Avatar
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    Guys your all over it! Well I'll make sure that is all sweet before I end up hitting the water

  6. #5
    A major cause is the fact that they had a typo in the service manuals for the torque value for the impeller. The 2003 manual had the torque as 92 ft lbs, which is correct. The 2004 and 2005 manuals dropped it to 59 ft lbs, which is insanely low. They corrected it in the 2006 manual back to 92 ft lbs.

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  8. #6
    Pete1027's Avatar
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    Quote Originally Posted by Slow 91 View Post
    pretty much the only thing that can cause a thrust failure is force on the crankshaft. I have seen it mostly due to props coming loose, broken motor mount. I also have seen people replacing all motor mounts, getting the alignment correct but not realizing the motor is too far back causing constant pressure from the driveshaft.
    How far back is to far back?? I have just done the alignment in my 10' TX putting the engine all the way back as people with this model seem to get light pressure on carbon seals resulting in slight leaks. I have less than 1/4" of float on the drive shaft

  9. #7
    steven mace's Avatar
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    Good guest ion Pete!

  10. #8
    steven mace's Avatar
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    Slow 91, been looking every where about 4 tec aligning.. i can see the shims to move the engine around but can i be moved forward and back? i did see in the older ski's (2 strokes im guessing) that the aligning bar had to be flush or inside the tooling bolted where the pump should be but cant find anything on the 4 tecs..

  11. #9
    Pete1027's Avatar
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    The factory workshop manual will tell you how to do alignment fore and aft using measured distances on the alignment bar.

    My problem is I used an aftermarket aligament rod and support plate which are slight different in design to the oem stuff. As a result those measurements will not be correct.

  12. #10
    steven mace's Avatar
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    cant see it in the manual dude.. might have to look in newer shop manual maybe.

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