Water coming out from sparkplugs on Mercury 1150

[Guztav123]

Hello! I just noticed when I was testrunning my 1976 1150 that there is water coming out from the sparkplugs, not all of them but almost. Is it the tophead gasket? Someone else that had simillar problem?

 

[Chris1956]

Re: Water coming out from sparkplugs on Mercury 1150

Everyone has that problem. The cure is to replace the waterjacket gasket, however, lots of time the 1/4-20 bolts break, and it is a real PIA to drill them out.

Usually we use some silicone caulk to seal the leak, and call it a draw.

 

[paulmiller_98]

Re: Water coming out from sparkplugs on Mercury 1150

Sounds like the head gasket to me.... and yep those bolts do break easily.

 

[Chris1956]

Re: Water coming out from sparkplugs on Mercury 1150

Paul, Those motors do not have removeable heads. They have a water jacket cover over the integral cylinder and block.

 

[Guztav123]

Re: Water coming out from sparkplugs on Mercury 1150

Everyone has that problem. The cure is to replace the waterjacket gasket, however, lots of time the 1/4-20 bolts break, and it is a real PIA to drill them out.

Usually we use some silicone caulk to seal the leak, and call it a draw.

Sounded good when the first word I read where that everyone has that problem, then it got a little harder to understand because of my not so good english

Water jacket gasket, is it the gasket under the engine top cover? If I only use silicon, where should I put that? Around the sparkplugs where I see water or should I remove the cover to put it instead of the gasket. Please explain a little easier. I am very happy for all the help I get!

Is there any risk of running the engine while there is water coming out? Any chance of water coming in to the cylinders?

Thank you very much for answers!

 

[Bob Gilvary]

Re: Water coming out from sparkplugs on Mercury 1150

No chance of getting that water into the cylinder.
Just remove the cover plate that is around the spark plugs and replace the old cover gasket with a new one.
If you run your engine in salt water, the bolts might be corroded and break. I just did this with a 25 hp engine that was fresh water run and 27 years old without a problem
Clean the surface of the block and cover plate good. Use a gasket sealer on both surfaces and tighten the bolts a little at a time, starting on the bolts closest to the spark plugs and work your way around to the outside bolts. Then start over with the bolts closest to the spark plugs and move on to the bolts on the outside.

Don't over tighten these bolts and break them off when you put it back on.

 

[Chris1956]

Re: Water coming out from sparkplugs on Mercury 1150

Gustav, Remove the spark plugs and clean the area around the spark plug with a solvent to remove the oil. Dry out the area real well, install the spark plugs and apply silicone caulk around the spark plugs, and let it dry before using the motor.

The water leak will not harm anything.

 

[wingnut4041]

Re: Water coming out from sparkplugs on Mercury 1150

Gustav, If you run your engine in salt water you may have overheated the engine,burning the watercover gasket, remove the gasket and replace it,check the surface around each sparkplug where the gasket seats for large pits from corrosion,if you have this problem,grind the corroision out down to clean aluminum and fill with "LAB METAL" Or "MarineTex epoxy".File flat to other surfaces. When salt water hits the plug wires or coils they will short out. If you just seal around the plugs with silicone and you install a new waterpump you could blow the sealant off and be back where you started!

 

[Chris1956]

Re: Water coming out from sparkplugs on Mercury 1150

Hey Wingnut, The silicone seal works just fine. The waterpressure in those old inline motors is not strong enough to push the silicone out. Also, the plugs don't short out. The fix just looks ugly with the white or clear silicone on the black paint. The answer is to use black silicone.

 

[Guztav123]

Re: Water coming out from sparkplugs on Mercury 1150

Thank you very much everyone for great answers!

 

[Guztav123]

Re: Water coming out from sparkplugs on Mercury 1150

Hi again! I did try to open the bolts just for fun. I sprayed some oil for a day or two, knocked on the bolts and tried unscrew them. There where I think 16 bolts and only two broke. I had to exchange three bolts but I where lucky that I could use Bolts with nuts on the back on the ones that broke. So I just drilled right thru.

I called my local mercury dealer but the gasket where pretty expensive and not even in this country so I used gasket on tube, liquid gasket and It worked fine. I had to remove allot of rust from both engine and cover so it where pretty much sand paper and rubbing. But the resault seems to be good, I tried the engine with no leaks!