ERRODED ALUMINUM- WATER SQUIRTING FROM AROUND SPARK PLUGS

[aoist]

The engine is 70 hp mercury outboard 700 in a 1958 Glasspar Club Mariner.I just bought this boat. <br /> So before I started up the engine I decided to go over the spark plugs and put fresh fuel in. and when I removed the plugs I noticed sealant around it and when I scratched it all off, I noticed some of the aluminum around the plugs were eaten away. Worse of it is that when I started up the engine, water was squirting out of all three plugs (through the holes in the aluminum around the plugs).<br /> I don't know much about outboard engines, but I know that isn't how it is suppose to be because I could see the water from the holes flowing down the plugs and the wires. So what do you think ? <br />Is there any hope this engine? Could it possibly be welded? If so how much of the outboard needs to be torn down? By the way I only ran it for several minites but the engine seems to run fine.<br />Thanks<br />Tom

 

[m_bickle]

Re: ERRODED ALUMINUM- WATER SQUIRTING FROM AROUND SPARK PLUGS

The best fix would be to helicoil the holes and replace the gasket for the cover. When you install the new gasket make sure the plate is not warped and use an RTV sealant, the problem will be solved. This is very common for quite a few Merc engines the water is from the water jacket around the cyl's.

 

[Merc805]

Re: ERRODED ALUMINUM- WATER SQUIRTING FROM AROUND SPARK PLUGS

If you attempt to remove the water cover, You WILL break some bolts and need to remove the powerhead for re-drill and tap. Just clean around the small holes and use JB weld. There is only 5-12 psi there and it will solve the problem.

 

[Chris1956]

Re: ERRODED ALUMINUM- WATER SQUIRTING FROM AROUND SPARK PLUGS

aoist, There is no removeable head on this motor. The aluminum that eroded away is from the water jacket cover, and will have no effect on the operation of the motor. It will however rust up your spark plugs and is not good for general corrosion purposes. I recommend that you put silicone caulk aroung the (driied and cleaned)spark plugs to cover the hole and let it dry overnight. When you feel like it you can remove the cover (you may end up breaking some bolts) and replace it with a new cover.<br /><br />PS, Sometimes the bolts on the cover have nuts fitted into the side of the block. On my 1977 inline 150, I had only two tapped holes (the bottom two), and the rest had room for me to drill out the broken bolts and use new 1/4-20 bolts with regular nuts.

 

[andrewkafp]

Re: ERRODED ALUMINUM- WATER SQUIRTING FROM AROUND SPARK PLUGS

If you don't clean up and seal them,the holes may get bigger and reduce your water flow and reduce pressure. And, if used in salt water it will make a mess of your plugs and rust the metal section.<br />I used a product called liquid-steel which is like JB weld and never saw a drop of water since.<br />If you change the cover, the bottom bolts are near impossible to remove (Bottom cowling in the way) without removing the powerhead. I'd go for the GOO.

 

[aoist]

Re: ERRODED ALUMINUM- WATER SQUIRTING FROM AROUND SPARK PLUGS

Thanks guys for all your kindly advice.<br />I think I'll try a cold weld of some type.<br />Tom

 

[KCLOST]

Re: ERRODED ALUMINUM- WATER SQUIRTING FROM AROUND SPARK PLUGS

You need to remove the cylinder cover (water jacket cover). And take care of the leaks... Hopefully you can find a new gasket for it, clean it up and your back in business. Your leaks are not coming from the spark plugs, but from the cover... If you had water coming out of the plugs, it wouldn't run...<br /><br />If there are pits where the gasket sits, then you can use some gasket sealer of some kind to fill them and create a good seal. But you must clean it thoroughly...<br /><br />Good luck.