1977 Merc 850. Water jacket question

[tallcanadian]

I've enclosed a couple of pics of the water jacket cover. As you can easily see there are a couple of cracks in it. I'm assuming that could be from overheating?? The one picture with the arrow, is pointing at a small hairline crack not on the water jacket but on the block side. Should I worry over this. My plan is to order in a new water jacket and bolts. I'm also ordering in new crank seals while I have this apart. The reason why I took this apart originally is because I was getting water in all 4 cylinders, even though I dont see any signs of water right now. Any help or info would be appreciated.

 

[Chris1956]

If you are getting water in all 4 cylinders, the issue is more than crank seals. The inner water jacket cover and/or the exhaust baffle will cause that, although I think it is an extreme case. I would look real hard for a crack in the block. Check under the transfer covers as well and see if the cylinder liners are cracked.


BTW those inner water jacket bolts are epoxied in, and are hard to remove, I recommend heat and gentle impact, plus penetrating oil and prayer.

 

[tallcanadian]

If you are getting water in all 4 cylinders, the issue is more than crank seals. The inner water jacket cover and/or the exhaust baffle will cause that, although I think it is an extreme case. I would look real hard for a crack in the block. Check under the transfer covers as well and see if the cylinder liners are cracked.


BTW those inner water jacket bolts are epoxied in, and are hard to remove, I recommend heat and gentle impact, plus penetrating oil and prayer.

Thanks Chris for the input. I removed an inner water jacket off a donor motor. It was tight but managed to get them all. However the motor is a different year and the jackets are different. I do see small cracks in the water jacket in those pics. But it looks like carbon fill them in. Not sure what is up with that. I don't see any rust in the cylinders at all. I just might can the 850, put it back together and use it for a lamp or something. I just don't know what I'm looking for.