Possible Cracked block?

[Kauaiboy206]

Been running my motor this season and never noticed this crack till now when I decided to clean up the outboard. It starts up just fine with no problem, could this be repaired or is it inevitable that I'm looking at a major problem waiting to happen? Can it be repaired or worth repairing it? It's an older 65hp merc thunderbolt outboard.

 

[jimmbo]

It is a four cylinder, that places it mid 1960s - 1972, which is 46 or more yrs old. If it looks bad on the outside, the inside should be worse. The bolts look a little too clean, either you recently put them in or someone else did. Not worth spending a lot of money on, as a complete good used motor would be gotten for less. But if you do want to fix it, you are going to need to find a donor engine, one that isn't all corroded up itself.

 

[Chris1956]

Stick some silicone on the crack to keep the water in. Run her until she totally fails.

JMO...

 

[Kauaiboy206]

It is a four cylinder, that places it mid 1960s - 1972, which is 46 or more yrs old. If it looks bad on the outside, the inside should be worse. The bolts look a little too clean, either you recently put them in or someone else did. Not worth spending a lot of money on, as a complete good used motor would be gotten for less. But if you do want to fix it, you are going to need to find a donor engine, one that isn't all corroded up itself.

the gentlemen before me kept this motor well maintained and always garaged and barely used it as he was on the older side. Was thinking of just using come sort steel putty like jb weld or something since I dont notice any power decrease or overheating.

 

[racerone]

Replace the exhaust cover gaskets.----Torque the bolts.-----Why do you think there is a crack ????

 

[Kauaiboy206]

Replace the exhaust cover gaskets.----Torque the bolts.-----Why do you think there is a crack ????

Not sure, that's just an exhaust cover? I'm not really too familiar with outboard parts etc. I take it to a shop for general maintenance,. If that's the case, can I get a replacement and just bolt it on?

 

[racerone]

It is an exhaust cover with water passages.-----It is cracked because water did not drain.---.Or corrosion products built up to the point it cracked this cover.----Lots of good used covers available if you know where to look.

 

[Kauaiboy206]

It is an exhaust cover with water passages.-----It is cracked because water did not drain.---.Or corrosion products built up to the point it cracked this cover.----Lots of good used covers available if you know where to look.

Looks like the part I need, its it pretty simple to change out?

 

[racerone]

Simple is a relative term. I have done this type of work many times.----I consider it simple on a fresh water motor.----I do not know your expertise or your workshop and tools available

 

[Kauaiboy206]

Simple is a relative term. I have done this type of work many times.----I consider it simple on a fresh water motor.----I do not know your expertise or your workshop and tools available

Not an expert but if it's just removing a few bolts here and there and putting on a new gasket and cover them shouldn't be too hard. Now if I had to remove more stuff like powerheads or major items to get to the water jacket then it may be just a job passing on to a decent mechanic.

 

[Chris1956]

The work is easy, if the bolts come out. Often on salt water and older motors, they prefer to break, rather than be removed.

I vote for silicone to seal it.

 

[Kauaiboy206]

The work is easy, if the bolts come out. Often on salt water and older motors, they prefer to break, rather than be removed.

I vote for silicone to seal it.

So rather than changing the water jacket, just applying some silicone over the crack is good enough? I've read on other post here that jb weld may fix it too.

 

[Chris1956]

Mercs do not have much water pressure. If the silicone doesn't get it you can graduate to JB weld or Marine-Tex. Try to just silicone the cover and leave the water passage intact.