Cracked head?

[79_banshee]

Hi everyone I have a 79 Mercury 1150 and I had it hooked up to the muffs running for about 15 min while I was checking it over I noticed water coming from around the #6 plug. Apon removing the plug there is no visible sign of water in the cylinder but if I turn the water on it will start coming out around the plug again. I moved the lower cowl down to get a better look at it and it starts at the top of the plug hole. Could this be the gasket. Any advice would be great. I'll try to load the vid I took of it

 

[jimmbo]

Welcome to iboats

Well first of all your engine doesn't have a cylinder head to leak, or even remove for that matter. What you are seeing, is a water jacket cover leak. It might be a bad gasket, but it often is a warped cover, and a new gasket will not seal well and the leak will come back. The warping happens if the engine has gotten too hot. Usually this leak happens at the top as this area is the first to get hot. Some people have had success using RTV gasket sealer in place of the gasket. I just got a new cover.

 

[79_banshee]

Ok thanks how much was a new cover. I'm new to the boating world. This is my first boat. I've worked on my own cars and trucks since I was a kid and have been working on heavy duty for the last 6 years so I am very mechanically inclined. Never really had money to take my stuff in to a shop to get fixed and I would rather know it was done right by doing it myself

 

[79_banshee]

Could the block be cracked or would that let water into the piston

 

[Texasmark]

Could the block be cracked or would that let water into the piston

Not hardly with that block. Water leaking around plug holes from the water jacket plate gasket is common. I cleaned up the mating surfaces real good and used a sealer for mine since, unlike new engines coming off the assy line where gaskets are installed dry, you no longer have nice, smooth, corrosion free surfaces.

Bolts usually try to snap if you aren't real careful. I like to crack the paint around them and give them a good soaking with a penetrating oil at least over night and then use a hammer "impacting" the end of a boxed end wrench till you get them moving a turn or two....more oil and then you can undo in the conventional manner. Chase the threads in the block with a tap and wire brush the threads on the bolts prior to reassy. Using a blue thread lock (Locktite for one) helps smooth the reassy and helps to prevent further corrosion.

 

[79_banshee]

A buddy of mine figures the block must have cracked cause it wasn't winterized properly and the cold froze it and cracked

 

[79_banshee]

Ok texasmark thanks did you put a new gasket in at that time or just used the sealant. Use like an rtv gasket maker or is there something specific.

 

[79_banshee]

Would any one know what the oil mixture is on this engine

 

[GA_Boater]

A buddy of mine figures the block must have cracked cause it wasn't winterized properly and the cold froze it and cracked

Outboards are self draining, so this can't happen. Water in a lower unit from bad seals can freeze and break the lower unit housing.

Would any one know what the oil mixture is on this engine

50:1 is the premix ratio.

 

[79_banshee]

Thank you for your advise GA_boater

 

[jimmbo]

Would any one know what the oil mixture is on this engine

As G_ABoater said 50:1. Use a good TCW-3 oil. No 2-stroke oil made for chainsaws, motorcycles, or snowmobiles

As for how much the cover was. I didn't pay anything, Mercury covered the cost even though the engine had been out of warranty for 2 yrs.

 

[Texasmark]

Ok texasmark thanks did you put a new gasket in at that time or just used the sealant. Use like an rtv gasket maker or is there something specific.

I use blue RTV and put a thin layer on both sides of the gasket before installing. I did not blob big globs of it onto the gasket which as others have protested, could wind up in and clog water passages.....a little common sense goes a long way!

I do not think this is the place for the RTV gasket maker as the lip is thin, there is water pressure involved, and that would require excess which could squeeze out into blobs and gobs that could clog passageways. Putting it on your truck/car oil pan, or differential cover, 2 uses for which it was made are different animals, wide flange to flange mating, and are not under pressure.

That's the way I see it and the way I do it.

 

[79_banshee]

K thanks a lot everyone. Would it hurt the engine to run it like it is for the rest of the season. I may only get out once or twice

 

[racerone]

Your buddy gave poor advice on the block being cracked from freezing !--------Yes you can run for the rest of the season with that minor water leak.

 

[79_banshee]

Ok thanks. I figured so cause there is still a steady stream coming from the tell tail hose at an idle or higher rpms

 

[Texasmark]

Your buddy gave poor advice on the block being cracked from freezing !--------Yes you can run for the rest of the season with that minor water leak.

Thanks, saved me from answering that as the powerhead drains when the engine is off, as does the rest of the cooling system.