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  1. #1

    Top dead centre measurement

    I'm trying to run a quick leak down test to get an idea of the state or my engine. I'm not able to do a full test right now, but just a cylinder comparison will give me an idea.

    If anyone has the chance to stick a wooden dowel in a spark plug hole and turn the engine to TDC, then measure the dowel where it comes out through the valve cover, it would be awesome for me to know this measurement.

    I have no way of turning my engine to TDC without separating the hull (remember I have an aS suspension ski so a PITA (and the best part of a day) to get to the SC nut).

    Once I have this measurement, preferably in mm as we don't have inch tools here, I can turn over the engine in drown mode, dip in the dowel and repeat test until I fall lucky at TDC.

    A long way around, but then I'll know the condition of the engine and if I need to open up the hull and run a full leak down to find the problem or wait until later.

    Would really appreciate a number, would also be worth checking all three cylinder measurements, just in case the top valve cover isnt a uniform, level design.

    Realise I'll need to be sure it's on the compression stroke not the exhaust, but I'll quickly find that out.

    Cheers
    Last edited by tornado34; 11-13-2014 at 11:28 AM.


  2. #2
    ricky86's Avatar
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    just an idea and thinking out loud. if you remove your steering nozzle,venturi nozzle and your pump cone
    you could turn your engine with the nut of the pump shaft so you don't have to turn the motor
    over 100 times to get the exact spot.

  3. #3
    Quote Originally Posted by ricky86 View Post
    just an idea and thinking out loud. if you remove your steering nozzle,venturi nozzle and your pump cone
    you could turn your engine with the nut of the pump shaft so you don't have to turn the motor
    over 100 times to get the exact spot.
    Good idea, I had considered this but wondered if it was "ok" to turn the engine via the driveshaft????

    That being said, with all the IBR fittings to be dragged off and I run oil in my cone, maybe cranking in drown mode may be quicker. Agree it could take a long time....yawn

  4. #4
    kkgregs's Avatar
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    Oct 2006
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    San Pedro Ca 90732
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    Just take off the valve cover and use your cam locking tool and go from there ,
    Ps I can test 1# like this but not 2# it leaks 3# leaks
    use your sc nut to tweak forward and backward .

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