Water jacket leaking at spark plus, OK to run?

java230

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So i noticed the gasket between the water jacket and the head seems to have gone bad. Its leaking pretty good from around the top spark plug. It still pees very well.

Will it be ok to run a few times like this while I find the time/parts to fix it?

Its an 82 40HP.
 

oldman570

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Re: Water jacket leaking at spark plus, OK to run?

It will run, but water and electrical units will suffer and could leave you paddling back to the dock and replacing more than just the water jacket gasket from damage to them. Best to wait till it is repaired and save yourself sore arms a maybe $$$ in the long run.JMO
Oldman570
 

jimmbo

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Re: Water jacket leaking at spark plus, OK to run?

It shouldn't do the engine any damage, as long as it is draining out of the cowl. The water it will just run down the back of the engine. Replacing the gasket might or might not fix the issue for long. Quite often the water jacket cover has warped a bit and it too needs replacing. When replacing the gasket do not put any gasket glue on it. Any time I used glue, it would leak again. Replaced without glue it never leaked again.
 
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java230

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Re: Water jacket leaking at spark plus, OK to run?

It will run, but water and electrical units will suffer and could leave you paddling back to the dock and replacing more than just the water jacket gasket from damage to them. Best to wait till it is repaired and save yourself sore arms a maybe $$$ in the long run.JMO
Oldman570

it doesnt seem ot be getting anything particularly wet. But very ture.


It shouldn't do the engine any damage, as long as it is draining out of the cowl. The water it will just run down the back of the engine. Replacing the gasket might or might not fix the issue for long. Quite often the water jacket cover has warped a bit and it too needs replacing. When replacing the gasket do not put any gasket glue on it. Any time I used glue, it would leak again. Replaced without glue it never leaked again.

It drains, just fills a little up. Im hoping its not warped...... so RTV is no good then huh? Seems strage to me that that would hurt.
 

jimmbo

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Re: Water jacket leaking at spark plus, OK to run?

I was refering to one of the gasket glues that merc marketed under their Quicksilver line, I guess RTV might work since there isn't too much chance of gasoline being there, except as fumes. Last time I changed it on my 84 115, the service manager told me to put it on dry. The gasket did have some sort of coating on it.
 

java230

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Re: Water jacket leaking at spark plus, OK to run?

I was refering to one of the gasket glues that merc marketed under their Quicksilver line, I guess RTV might work since there isn't too much chance of gasoline being there, except as fumes. Last time I changed it on my 84 115, the service manager told me to put it on dry. The gasket did have some sort of coating on it.

can you get the cover off withour pulling the powerhead? The bottom two bolts seem pretty buried.....
 

emckelvy

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Re: Water jacket leaking at spark plus, OK to run?

You can do an emergency repair by filling the gap betwen the spark plug and cover with RTV. This will seal it temporarily until you can do a proper gasket replacement.

The Hi-Temp red RTV should do a good job, just don't use Ultra-Copper since the aluminum and copper don't mix well and can cause galvanic corrosion.

Be sure to degrease with a suitable solvent (carb cleaner, etc) for best adhesion.

HTH...........ed
 

jimmbo

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Re: Water jacket leaking at spark plus, OK to run?

img016.jpg

Here is my 115 with the jacket off, I did remove/move parts of the cowl support
 

Texasmark

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Re: Water jacket leaking at spark plus, OK to run?

I had a late model 115 that leaked for awhile. I finally replaced it and to ensure no problems covered both sides with a thin film of blue
RTV after I cleaned off all the corrosion on the surface.

Only problem I had with the engine in 7 years.

Mark
 

jslu

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Re: Water jacket leaking at spark plus, OK to run?

Java
I had the same problem with a 1989 35 HP Merc which is pretty much the same engine block as your 82 40 HP. I tried going the RTV route by sealing around both spark plugs (proper cleaning of these areas is very difficult) but was only 50% successful. I finished the boating seaon this way with no adverse effects on engine performance, fresh water use only.

At the end of the season I replaced the gasket (dry fit) after cleaning both mating surfaces and ensuring the "head" was not warped. Yes, you can do this witout removing the power head. Patience is reqiuired for the two bottom bolts. Torque in sequence per the factory manual and you should be good to go .Two years for me so far without leaks.

John

So i noticed the gasket between the water jacket and the head seems to have gone bad. Its leaking pretty good from around the top spark plug. It still pees very well.

Will it be ok to run a few times like this while I find the time/parts to fix it?

Its an 82 40HP.
 
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java230

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Re: Water jacket leaking at spark plus, OK to run?

Java
I had the same problem with a 1989 35 HP Merc which is pretty much the same engine block as your 82 40 HP. I tried going the RTV route by sealing around both spark plugs (proper cleaning of these areas is very difficult) but was only 50% successful. I finished the boating seaon this way with no adverse effects on engine performance, fresh water use only.

At the end of the season I replaced the gasket (dry fit) after cleaning both mating surfaces and ensuring the "head" was not warped. Yes, you can do this witout removing the power head. Patience is reqiuired for the two bottom bolts. Torque in sequence per the factory manual and you should be good to go .Two years for me so far without leaks.

John

Thanks John,
I think this is the route i will be going.
 

java230

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Re: Water jacket leaking at spark plus, OK to run?

Java
I had the same problem with a 1989 35 HP Merc which is pretty much the same engine block as your 82 40 HP. I tried going the RTV route by sealing around both spark plugs (proper cleaning of these areas is very difficult) but was only 50% successful. I finished the boating seaon this way with no adverse effects on engine performance, fresh water use only.

At the end of the season I replaced the gasket (dry fit) after cleaning both mating surfaces and ensuring the "head" was not warped. Yes, you can do this witout removing the power head. Patience is reqiuired for the two bottom bolts. Torque in sequence per the factory manual and you should be good to go .Two years for me so far without leaks.

John

Went to try to replace the gasket today. What a poop show. After soaking in PB I've got two broken bolts so far. Now how do I get the lower engine cover piece off?
One of the broken ones is the very bottom bolt. Now I have to try to drill and tap it. Do I need to drop the lower to get that cover off? Seems the lip on lower keeps that piece from dropping down.....
 

Chris1956

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Re: Water jacket leaking at spark plus, OK to run?

The lower cowling will only come off if you pull the powerhead. Remove the cowling support (6 bolts) and 4 SS screws holding the bottom piece of trim, and the lower cowling will move around a lot more.

A lot of those blocks can be thru-drilled and 1/4-20 bolts and nuts used to install the water jacket cover. Only a couple of them would need to be tapped.

Use a propane torch (don't set the motor on fire) and the PB Blaster. As the bolt cools, it will suck some of the blaster into the threads. It may work better. Use some gentle impact from a hand-impact driver as well to help loosen the bolts. Saying a prayer to your God, can also help.
 

java230

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Re: Water jacket leaking at spark plus, OK to run?

The lower cowling will only come off if you pull the powerhead. Remove the cowling support (6 bolts) and 4 SS screws holding the bottom piece of trim, and the lower cowling will move around a lot more.

A lot of those blocks can be thru-drilled and 1/4-20 bolts and nuts used to install the water jacket cover. Only a couple of them would need to be tapped.

Use a propane torch (don't set the motor on fire) and the PB Blaster. As the bolt cools, it will suck some of the blaster into the threads. It may work better. Use some gentle impact from a hand-impact driver as well to help loosen the bolts. Saying a prayer to your God, can also help.

Did heat, and PB, sprayed it down again this morning and will try again tonight. Im not feeling hopeful however. They all felt very tight still this morning. Bringing the mapp torch home today.

We will see how it goes. All the one see can see without removing the lower cowling i could see the back side of the bolt. This does make it a bit easier to drill and tap it again.
 

spencer321

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Re: Water jacket leaking at spark plus, OK to run?

I just recently had to remove this cover chasing an overheating issue, i broke 8 out of 10 bolts after a week of heat, tap tap, pb blast etc every single day multiple times a day, there comes a point where it doesn't matter what you do, they are going to break, just take your time and be as careful as possible with the bottom 2, the others are easy to drill out
 

java230

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Re: Water jacket leaking at spark plus, OK to run?

I just recently had to remove this cover chasing an overheating issue, i broke 8 out of 10 bolts after a week of heat, tap tap, pb blast etc every single day multiple times a day, there comes a point where it doesn't matter what you do, they are going to break, just take your time and be as careful as possible with the bottom 2, the others are easy to drill out


Not a good sign. Mine has been in salt too.... And the very bottom one already broke. Does that one not go through like the others?

Ill likely be trying to pull the powerhead tonight. Wife wants it running. Should have waited till winter to do this.....
 

Chris1956

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Re: Water jacket leaking at spark plus, OK to run?

You may need to break down and buy yourself a drill press. The bolts are a lot easier to drill out, with one of those.
 

java230

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Re: Water jacket leaking at spark plus, OK to run?

You may need to break down and buy yourself a drill press. The bolts are a lot easier to drill out, with one of those.

I have access to a drill press if needed. However im hoping i can leave all the accessories still bolted tot eh PH and just lift the head side up enough to work on the lower bolts. May not be possible but we will see!
 

spencer321

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Re: Water jacket leaking at spark plus, OK to run?

Im in the same boat right now working on my last bolt which is one on the bottom, drilling them out by hand isnt hard just grind the bolts flat, take your center punch and get a good center. Take your time. If you manage to get the powerhead on one side please let me know. Im currently trying the weld a nut trick with no luck
 

java230

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Re: Water jacket leaking at spark plus, OK to run?

Im in the same boat right now working on my last bolt which is one on the bottom, drilling them out by hand isnt hard just grind the bolts flat, take your center punch and get a good center. Take your time. If you manage to get the powerhead on one side please let me know. Im currently trying the weld a nut trick with no luck

Ill let you know. Im going to go at it tonight. Its nice out, wish i had waited till the winter to do this.... I may just drill the cowling if i can get the other lower ones out.
 
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