'76 Merc 500 pinhole in water jacket

[Rookman]

I have water coming out of my spark plug where the gasket failed. Upon removal of the cover, it appears there is a small pin hole in the bottom of the water jacket that leads to a reservoir that is covered by the gasket. Is this pinhole factory and what is that reservoir? Got lucky on bolts not breaking by the way.

 

[rabeck5792]

Re: '76 Merc 500 pinhole in water jacket

no it is not factory.if the plate is eroded,get a new plate & gasket.some are no longer available.i have J B welded many of them & had good success.make sure plate is flat & use perfect seal on new gasket.

 

[Rookman]

Re: '76 Merc 500 pinhole in water jacket

Thank you Rabeck. Gonna go after it when the rain stops.