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  1. #1
    monaroman76's Avatar
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    More problems!! Exhaust valves ....

    Hey guys, just as the weather is coming good down here in Australia, I was adding the final touches to my setup when I came across another problem

    I was in the process of installing the Riva valve train (well hadn't started really) and upon pressurising the rear cylinder, I found that I was losing a lot of pressure really quickly.
    It didn't take too long before I realised it was passing the exhaust valves. Its not just a slight leak either, when I hold my hand over the water box I can clearly feel the pressure behind it.

    It looks like I will be pulling the head to see whats going on... Does anyone have any ideas or suggestions before I go ahead and do this? This sucks !!

    Cheers.


  2. #2
    West Texas RXP skoepp's Avatar
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    Are sure the valves were closed.

  3. #3
    monaroman76's Avatar
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    Quote Originally Posted by skoepp View Post
    Are sure the valves were closed.
    The rocker shaft had already been removed..

  4. #4
    monaroman76's Avatar
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    I only changed the head gasket maybe 7-8 hours ago, while the head was off, I had it decked and had the valves checked and tested to make sure they were sealing.

    This all happened maybe 6 months ago...

  5. #5
    Work Harder, Millions on Wellfare Depend On Us! ultramaxracing05's Avatar
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    It would not hurt to lap in the valves and them go from there. Cheapest way out.

  6. #6
    dnielsen's Avatar
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    Try flipping a screwdriver over so that the handle is pointing down while tapping on the top of the valve stems to see if they will seat. Do this while pressured up, could be the valves are slightly sticking. Did this the other day and all turned out well. Dont get to crazy with tapping the stems, just enough to crack the seal on the valves.

  7. #7
    monaroman76's Avatar
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    Quote Originally Posted by dnielsen View Post
    Try flipping a screwdriver over so that the handle is pointing down while tapping on the top of the valve stems to see if they will seat. Do this while pressured up, could be the valves are slightly sticking. Did this the other day and all turned out well. Dont get to crazy with tapping the stems, just enough to crack the seal on the valves.
    I tried this already, maybe I should be a little more persistent and hope it works.
    The spark plug from this cylinder seemed blacker than the others also. I was thinking that if there was an issue with the exhaust valves, the plug may have got like that due to exhaust gasses being present in the cylinder.

    Would it be best off to just purchase new valves or will I not really know til I pull the head? Can I lap the existing valves?
    My motor has 117hours

  8. #8
    monaroman76's Avatar
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    Ok, so i've pulled the head and found that the valve seats dont look too pretty....
    Where do I go from here? I was thinking I would get the valve seats cut and get Ferrea valves.

    Any input from the pros would be greatly appreciated

  9. #9
    monaroman76's Avatar
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    pics

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  10. #10
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    Looks like just a lot of buildup from running really rich...I say clean it up good, and lap them...If there is no pitting or damage to the seats, and if the valves are not bent and are good and straight, should be a quick fix...Lap them all

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