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Hot!no compression 3hp

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ennisdavis
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2016/10/22 16:37:45 (permalink)
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no compression 3hp

I rebuilt an engine and the compression is zero. I aligned the cam and crank marks. Lapped the valves and they seem to be closed at top dead center. Put some compressed air thru the spark plug hole and it appears to be leaking out of the exhaust valve a little. You would think I could get a little compression. What am I missing?

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    Mikel1
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    Re: no compression 3hp 2016/10/22 21:05:18 (permalink)
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    Are you sure your getting zero compression? Compression tester?
    Leak down tester would tell you for certain where the problem lies. Leaking some out of the valve will not get you zero compression.
    ennisdavis
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    Re: no compression 3hp 2016/10/22 21:27:09 (permalink)
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    3 different testers. Zero. At tdc air is coming out of exhaust. These valves are not adjustable on 3hp engines, right.
    Mikel1
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    Re: no compression 3hp 2016/10/22 22:24:15 (permalink)
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    Not sure what engine this is.
    On ohv you can adjust valve clearances easily, L head(flathead) you can grind stem to achieve valve clearances if clearances are too small.
    post edited by Mikel1 - 2016/10/22 22:52:17
    Roy
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    Re: no compression 3hp 2016/10/23 19:48:27 (permalink)
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    First of all, verify that the piston is in fact at the top of the compression stroke. Did you reface or replace the valves? Did you cut the valve seats? If yes to either question then you need to adjust the clearance by grinding the stem tips, take your measurements with the piston just past top dead center.
    Mikel1
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    Re: no compression 3hp 2016/11/02 10:07:10 (permalink)
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    Briggs 10T802
    Both valve stems ground down, compression now 60
    post edited by Mikel1 - 2016/12/02 10:13:49
    Mikel1
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    Re: no compression 3hp 2016/12/02 10:15:43 (permalink)
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    Updated
    dreamcompressorses
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    Re: no compression 3hp 2016/12/08 00:44:38 (permalink)
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    Are you sure need to get no air compressor?The normal it is difficult to do,only if you have very good valve and some tester machine
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