Valve Lubricant

[Mark R.]

1996 MerCruiser 4.3 LX Gen+
Operation & Maintenance Manual # 90-807795962. On page 51 it states:
"To maximize the life of valves and valve seats on your MerCruiser engine, use Quicksilver Valve Lubricant (92-90131A12) regularly."
It appears this P/N has been superseded by P/N-826259A12, but that appears to be unavailable also.
Do you guys use any type of valve lubricant added to your fuel fills..?

 

[Scott Danforth]

No, haven't needed any "valve lubricant" since 1974

 

[Chris1956]

I used to run some marvel mystery oil in my carbed Merc 4.3LX. When that ran out, I ran 2 cycle oil at the same ratio. Whether it did anything for the valves, I do not know. I thought it might keep the rust down in the intake manifold, though.

 

[bajaman123]

Marvel Mystery Oil is simply incredible...highly recommend its use. Likely the Mercruiser valve lubricant product is NLA is due to catalyst damage potential.

 

[Mc Tool]

I used to use a lead substitute in my pinto Capri engine because it doesnt yet have hardened exhaust valve seats . Works well too , without it I lose about a thou of valve clearance per 1000km's. That engine is not in use now .

 

[Scott06]

Looks like lead substitute they recommended when leaded went away , decades ago… that part number and the superseded part numbers are NLA. A1996 will have hardened valve seats from the factory so not sure if you are using the correct manual for your engine

 

[airshot]

I used Lucas Fuel treatment in my 3.0, not as a valve lube, even though it is, but as a fuel conditioner to keep out water and clean combustion chamber.

 

[Mc Tool]

I used Lucas Fuel treatment in my 3.0, not as a valve lube, even though it is, but as a fuel conditioner to keep out water and clean combustion chamber.

Yeah , according to the blurb on the bottle it was a cure for everything fuel related , damn I cant remember what it was . I started with valvemaster but then that went off the market ( here ) and I think it was Redline that I went to next ...not sure ...the bottle is still tucked down the side of the drivers seat but the car has been parked up in a shed where I cant get to it since I got my leg chopped off ......aint it amazing how crap gets piled on top of anything that doesnt move for a while .