Mystery Oil Leak - merc. 470

Spare_Time

Cadet
Joined
Jun 25, 2008
Messages
21
I have a mystery oil leak (on my merc 470) that looks like its coming from the valve cover however I JUST replaced the valve cover gasket and its still leaking. The oil is "pooling" up on the lip of the intake manifold and running down the carburetor side of the block. Im completely new to this engine and boating but have a fair mechanical background. Anyone else have a similar issue?

On a side note, i've been having a hot-start issue. Is this common as well? I added a second battery as a band-aid but this hasn't completely resolved the issue....just checking! ;)

ooh, lastly since I don't know much about this motor, what is a good idle rpm? Right now im having a real tough time keeping the motor running at 750rpm. Any thoughts? Carb need to be cleaned????


THANKS!!!!! this forum is awesome. Happy Boating everyone!
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,090
Re: Mystery Oil Leak - merc. 470

A),... Oil drips Down,.... Find the Highest point of the oil,+ the Leak will be There....

B),... It sounds like the motor is Out of Tune,+/ or the Wiring is Corroded....

C),... 650/ 750rpms...... See (B),... Tune it Up,+ Possibly rebuild the Carb...
 

Spare_Time

Cadet
Joined
Jun 25, 2008
Messages
21
Re: Mystery Oil Leak - merc. 470

A),... Oil drips Down,.... Find the Highest point of the oil,+ the Leak will be There....

B),... It sounds like the motor is Out of Tune,+/ or the Wiring is Corroded....

C),... 650/ 750rpms...... See (B),... Tune it Up,+ Possibly rebuild the Carb...

Thanks!!!! as for the hot-start, i forgot to mention it was a starting motor issue. Motor cranks for a 1/2 a sec. then binds up like it has a high spot and whines. I know enough about electrical motors to know that the motor is demanding more current than my battery is supply thus the whine. Continuing to hold the starter can only result in melted battery cables and a possible burned out starter (been there before with my Oldsmobile :( )

Any ideas as to why the starter does this? LIke I said in my first post, I added a second battery for a current boost however that's not really solving the problem per-se. Its just giving the starter that extra jolt of current it needs to get moving ;)

As for the oil leak, i've looked and looked. I swear its got to be coming from the valve cover. Is it possible it could be coming from the intake manifold somewhere (not actually from the intake manifold because it would be sucked in, i know that), like is there an oil port around the intake that could be leaking? I don't know much about this motor as I've said earlier.

Thanks Again! :)
 
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