Water jacket corrosion

[Dmzhmdepo]

I have a 74 - 40hp Mercury. Just had the cowling off and noticed a very small / very slow drop of water coming out from under the lower spark plug while running on ear muffs. Just removed the water jacket cover and see corrosion on the cylinder head where the jacket and gasket fit aroung the plug hole. Am I going to need a new cylinder head? Say it ain't so!<br />Thanx in advance. Dmz

 

[12Footer]

Re: Water jacket corrosion

No, DMZ, you don't need a new one. But it WILL have to be resurfaced. Any good auto or marine machine shop can do this fairly cheap. I would be more concerend with WHY this happened ion the first place. Like an overheating problem, a blocked coolant port, or missing or inoperative tstat.<br />When u get her back together, get the manual,and make sure the water pressure is within spec.<br />If not, you need to find out why.<br />On a more positive note, you should be congradulated for catching this in time.

 

[Dmzhmdepo]

Re: Water jacket corrosion

Thanx 12ftr.<br />I really like this old motor and don't want to give-up on her just yet.