4 Stroke block damage

[bbezok]

A Friend of mine attempted to change his water pump on a Merc 4-stroke 115hp after the dealer told him 8 weeks before he could take it. Well apparently, when he tightened the lower back in place the shift shaft wasn't seated properly, and it punctured the block and now leaks oil. He spoke with the mechanic at the dealership after the damage was done and he knew just what had happened. I told him I would ask the brain trust on here as if it can be repaired, someone on here would know. Is it junk or can or has anyone been able to repair the block?

thanks,
Bill

[LakeFever]

Anything is repairable. If the block is broken in a non pressurized portion of the block that holds oil that is the best case scenario. If it’s broken on the pressurized part of the block ehhhh that’s no so good. Still repairable but more involved. If the block is aluminum this is easier than if it’s cast iron. Either way this power head has to come off and inspect the best plan forward from there

[Se7]

Have seen this scenario a number of times while working in the field. Most likely broken the boss off at the bottom of the aluminum crankcase. Have seen a number successfully repaired by experienced welders. As mentioned the PH has to come off. Good luck.

[JPEROG]

JB

Joe

[bbezok]

We're located in southern Mass, I had Ronnie Holzmacher out on Long Island do the nose cone on my lower last year, he's a magician when it comes to welding anything. I suggested he contact him.

[merccrazy]

He won't do that again.

[Chaz]

All aluminum castings can be welded. The newer ones seem to be made out of Mercatinjunkslagaloy, but it is weldable. Like all aluminum it needs to be clean, clean, clean. The last thing to touch the parent surface should be a carbide burr. Preheated and welded with 4043 filler rod.

As Joe mentioned, you can use JB weld or Splash Zone .. same basic prep applies. Glues work good until the day they don't. This guy brought me this tank from his dyno cell the other day to build him a new one. I guess he got tired of fixing leaks ...

[JOSEPH SHULMAN]

Chaz, Have you had an success in repairs a busted 300x block?

[Chaz]

For a while Merc thought they were OMC and tried shoving 300xs sleeves in cold. Yes, some came off the assembly line with split registers. The ones that didn't get sent back to the factory to be crushed were a pretty easy fix.

That one you have there more than likely knocked the floor out of it (rod slot) and might have gotten a crank sealing ring bore as well. All those areas can be fixed, up to a point. And at a certain point it might be cheaper to look for a replacement block.
Take some pictures when you get it apart.

[Chaz]

You can see where compression has leaked around the sleeve and water made it's way into the cylinder.



Welded up, bored for an oversized sleeve and then bored + honed back to standard. (they come.050 small ID) Head mating surface decked flat .. good to go