water coming out around top spark plug?

[gregbarkley]

I have a 1979 mercury 40hp motor and I did some work on it and now when I start it up, water comes out around the top spark plug. Yes, the the plug is in tight and in all the way(new head gasket too). Also I think I'm missing a hose because water is not coming out the pee hole, but out another hole on the other side of the motor. (yes the water pump works) please help! I can't afford a new motor

 

[JB]

Re: water coming out around top spark plug?

Howdy and welcome. <br /><br />I will move this to Merc Troubles for you.<br /><br />Good luck.

 

[Clams Canino]

Re: water coming out around top spark plug?

Since you said had that cover off already (you called it a head though) take that cover off again and use some black silicone seal around the plug holes on both sides of the new gasket you're gonna buy. That's a common leak. <br /><br />You may need a hose fitting or a brass plug depending on what hole is what. <br /><br />You're gonna have to be able to afford the manual to not have to afford a new motor. Also your Merc dealer outta be able to get you the right water pee hose parts easily.<br /><br />-W

 

[jurgenscraft]

Re: water coming out around top spark plug?

I have heard of cracks developing around the spark plug hole because of incorrect tightening , maybe this might be the case.You never stated if the leak was from the spark plug hole proper or from the casting area around the spark plug, if the water is comming out of the spark plug hole itself, this tends to indicate a gasket problem, failure or incorrectly fitting . ie. Water being allowed from the water jacket into the combustion chamber. Strip the cylinder head off the motor ,have it cleaned and then crack tested, if all is in order, then reassemble using a origional gasket and recomended gasket sealers / cement,remember some gaskets are maufactured so as to eliminate the use of silicone type sealers, they are already coated with a substance, that when under pressure will assiat sealing,then all should be in order.<br />Kind Regards.<br />William Wright.

 

[fishingdan]

Re: water coming out around top spark plug?

I freaked out when I saw the same thing on my 1985 50 hp mercury. I not familiar with your engine, but let me explain my situation and you can determine if it applies. If yes, you need a new gasket and the repair is easy.<br /><br />- The top sparkplug "hole" is key hole shaped where the others are round. <br /><br />- Water is coming from the small end of the top sparkplug hole and appears to be coming from a small hole next too the plug.<br /><br />If this is the case, your engine is similar to mine and you need to replace the waterjacket gasket. The water is not really coming from the hole near the plug, but from a breach in the gasket in that area. The new gaskets have a lot more support in that area and they also have some heat activated glue on it. I also applied a gasket sealer before putting it all back together.<br /><br />Good luck.<br /><br />