adjusting valves on 1986-89 3.0l mercruiser

slredstorm62

Seaman
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Jul 28, 2009
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i have been replacing the headgasket on a 1986-1989 four winns 160 freedom with a 3.0l mercruiser. i was told i had to adjust the valves before running the engine. only problem is i have no idea how to adjust the valves. i have been reading up on it and some people say zero lash and others to do it on compression stroke. i am an automobile technician so i know some stuff abou tthe engine but i have no idea what zero lash is or how to tell if i am on compression stroke. is tdc when pistion is at the top of head?
 

Don S

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Aug 31, 2004
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62,321
Re: adjusting valves on 1986-89 3.0l mercruiser

Have you considered reading the Mercruiser service manual? It tells how to do it.
Just head up to the Adults Only sticky at the top of this forum and download the manual. You want #10 for your engine. Might as well get #6 for your drive as well. You may need it too.

i am an automobile technician so i know some stuff abou tthe engine but i have no idea what zero lash is or how to tell if i am on compression stroke.

That is basic engine knowledge, even in the automotive industry.
 

JustJason

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Re: adjusting valves on 1986-89 3.0l mercruiser

i am an automobile technician so i know some stuff abou tthe engine but i have no idea what zero lash is or how to tell if i am on compression stroke

jiffy lube, meineke, pep boys, midas, or goodyear?
 

Bondo

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Re: adjusting valves on 1986-89 3.0l mercruiser

Quote:
i am an automobile technician so i know some stuff abou tthe engine but i have no idea what zero lash is or how to tell if i am on compression stroke
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jiffy lube, meineke, pep boys, midas, or goodyear?

Ayuh,.........:D :rolleyes:
 

wvmedic

Chief Petty Officer
Joined
Jun 3, 2008
Messages
465
Re: adjusting valves on 1986-89 3.0l mercruiser

Gavin check out this thread, it will explain zero lash.

http://forums.iboats.com/showthread.php?t=357665

Compression stroke is what is says, when rotating the crank assembly with the spark-plug out you should hear compression from that cylinder. You can also place a finger over the spark-plug hole and feel compression.

TDC = Top Dead Center.

Jeff.
 
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