165 hp Mercruiser tappet settings????

[Skipster1]

My Merc is making a bad tapping sound under the valve cover. Probably a tappet going bad? I need to know the setting for the tappets on this engine. The serial number is: 4460527.<br />Does anyone know offhand? Or know of a good link for the specs on this engine?<br />The sound is so loud.... could it be another problem?<br />Thanks....

 

[deckhand]

Re: 165 hp Mercruiser tappet settings????

Sounds like you have a lifter that has gone bad and is no longer holding oil pressure- if one goes others are not far behind- general rule change them all. The best adjustment is running- back off nut until clatter starts then slowly!! no more than 1/4 turn at a time until noise just stops - this is zero lash position- then 1/4 turn pause until engine runs smoothly again then another 1/4 turn until you have reached a total of 3/4 turns- is factory spec this serial #. If you do replace all lifters there is a sequence you have to follow to get zero lash to start with so that the engine will start and run. If you decide to go that way post it and I will give you the sequence.

 

[JB]

Re: 165 hp Mercruiser tappet settings????

Moving to I/O