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Mystery compression hiss ES2.

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Turning ES2 1952 engine over by hand on kickstart, heard a hissing sound first thoughts" oh know," head gasket blowing.More investigations found that the oval tappet cover not quite sealing properly as I put new cork gasket on few months back.As for kickstart compression on TDC what's the reasonable hold time on kickstart. Thank's also for your replies on rear chain tension.  Barrie

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There shouldn't be any pressure inside the rocker box so if there really is, there is something wrong. My ES2 makes a sort of hiss when turning over but it is air being sucked in through the carburettor. As there is no air cleaner you hear it more. Does the engine run OK?

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You can get a certain amount of positive and negative pressure in the rocker box, but this will be from air under the piston as it goes up and down trying to find the easiest way in and out.. If there is any pressure coming from the valves then as Ian says, you have something very strange going on.

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Thank's for all the replies,yes the engine runs fine .There must be crankcase pressure as piston goes up and down that would be normal I think pos & neg as Tony suggested, causing hiss from from tappet cover not tight enough,breather valve seems ok ,here it working no oil blowing out .Very good comp on kickstart, holds comp tdc for about 10 secs or more.unscrewed tappet cover hiss disappeared,that's how I found out.

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You won't be eligible to call your steed Sid now!
I have a weakness for these outbursts, please forgive me!

 



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