Mercury 500 broke one of the rods

[luckys pinstriping]

Good Afternoon.
I have a 1968 Mercury 500 thunderbolt. The connecting rod on #3 cylinder broke and a small piece wen thru the case. I have not taken it apart to see the extent of the damage which i am sure will be interesting.

Anyone have any suggestions on a repair?

I know i need at least a new rod and piston and engine cases.

Can i take my crank with a new rod and piston and put it in another set of cases?

Should i just replace the whole powerhead?

And last worst case scenario if i need another powerhead where should i look?

Thanks for the help

 

[flyingscott]

Find a different motor.

 

[DeepCMark58A]

Finding even a replacement powerhead will be difficult. Time for a new motor.

 

[racerone]

Depend on your location.----Might not be that hard to find the parts.------If the rod broke likely the crankshaft is kaput too.-----Have you worked on a motor like this before ??

 

[luckys pinstriping]

Good morning, Thank you for the replies.

Racerone- I have done some work on this motor but nothing internal yet. My plan was to tear it down and determine the damage internally. The rest of the motor is good i rebuilt most of it including the lower unit. All electrical reworked replacing all the corroded wires.

I have fond a couple power heads ranging from $200-$500. My thought is i can drop that into what i have now. I think it will cost far more to try and repair the internals crank, bearings, rods, pistons, rings etc.

Any thoughts?

 

[Scott Danforth]

you ventilated the old block, the old power head is junk

the cheapest way to fix this is buy a good running power head, or for about the same money, upgrade to a motor a few decades newer

 

[luckys pinstriping]

Well tore the old boy down last night. Broke a rod rights at the crank. Chewed up the crank and the skirt of the piston. Interesting though the other three cylinder's and pistons look great. I assume the needle bearing's let go causing the rod to break. Any idea what would cause this? With the rest of the internals in great shape it seems odd the it would let go.
As you guys indicated above will now be looking for another 50hp motor to install. Any suggestions on a motor and if so where to find one?

 

[jimmbo]

There 2, 3, and 4 cylinder 50hp, pre 1986 were crank rated, post 85 prop rated. 2 stroke and 4 stroke. Mercury, Evinrude, Johnson, Mariner, Yamaha, Suzuki, to name a few. Which one is best? They are all good motors, but they all have their Weaknesses. Everyone on this Board has their opinion as to which is the best, I know I do. But if I say Brand is X is Perfect, and you get one that is a Lemon... Do some Homework and then try to find a well maintained engine. Be Aware that as Engines get old, the availability of parts can become an issue, as can getting it serviced. Dealers often have Used Engines and often will offer a short Warranty, at least till the engine is off the Property

 

[racerone]

location , location.?

 

[luckys pinstriping]

Thank you for the replies
I am in Ohio near Cleveland. I will start looking out there to see what i can find without paying a fortune. Our boating season here is winding down but i walleye and steel head fish lake Erie well into December. So hopefully i can find something soon.