Small hole in mariner block

[jm_middleton]

I purchased this boat in November. Iv'e had it out probably 10 times this winter with no issues. It's always been hard to start the first time of the day. After that it fires right up. I put new plugs in it and took it out for a few minutes today. It seemed to run fine. I got it home checking everything out and noticed some oil. The oil could have been there since I got it but then again it might not of either. I noticed a small hole in the block. I did a compression test and got 120 psi on both cylinders. Is this a hole that can be fixed or is it caused by something more serious that will lead to failure?
The engine is a 1988 mariner 40ELO.

 

[jimmbo]

Looking at the image enlarged, I would say there was an Impact, probably by the Connecting Rod. The engine needs to come apart, as something happened inside. As for "patching it up", depends what happened, the casting might be weldable, but...

Edit: Looking at the pic again, there are bunch of Cracks in the surrounding area. I would say the block is toast

 

[jm_middleton]

I didn't notice the additional cracks. Is it possible I've been running it with the block busted the whole time? What is the most likely cause of this? It sat for 10 years before being used by me. Did something internal seize and break? Could over heating cause this? I could tear the engine down but is that going to be the least expensive method is to repair? I can pick up a used power head for around 500 to 600. Sorry for all the questions but I'm sure the wife will kill me. My son is heartbroken but we still can fish from the bank.

 

[racerone]

Picked up a 15 HP Mariner 15 years ago.----Had a hole in the block.----Parts motor ?-----Then when I took it apart I saw what happened.----Welch plug came out of the crank and jammed between rod and block.-----Made a new plug and installed it very securely.---Repired hole in the block with " Lumiweld " brazing rod.----Motor is still running , only gets used on a dingy in summer.-----You have to take it apart to see what happened.----Or just run it if it is not making mechanical noises.

 

[Texasmark]

You say a hole in the block, is it a hole and water is spewing out when the engine is running, or is it just a non functional casting flaw? That looks like a water jacket area to me, not part of the combustion chamber, fuel air intake, nor exhaust. On oil inside the engine compartment, that could have been from several sources, one could be aged fuel lines that are leaking, another leaking oil if you have an onboard (the engine) oil tank, carburetor float not sealing the bowl and when the engine is tilted up fuel spills out the carb throat......type things.

 

[racerone]

Fact----JM is saying he sees a hole / crack / leak here.-----I see a location where the connecting rod swings near the crankcase side.-----Up to JM to decide what to do here.

 

[jm_middleton]

It only looks like oil has been coming out of it but I haven't watched it while it was running either. racerone is right that it is by the connecting rod. Will I be able to check the internals by pulling the carbs and reeds out? Or will I need to crack the case to be able to inspect it?

 

[racerone]

Removing reeds may allow you to look inside.--------And there are fancy cameras that allow you to look inside too.

 

[Buckischloo]

You might also check out the attachments for cell phones to make them an inspection scope, borescope, endoscope. Not too expensive, around $35. I picked up a Lizard Cam Micro inspection cam at Menards at Christmas for under $20. I have not used it yet but my hope is to be able to look at the insides my motors to see what is going on.

 

[jimmbo]

It looks like there are two holes

 

[jm_middleton]

I ordered a small camera that hooks up to my phone or laptop. It should be here tomorrow. I have been looking online for parts and found some blocks. After looking at the pics of the bare block how did I end up with a hole in between where the connecting rods are? It looks like that area is solid unless I'm not looking at it correctly.

 

[Texasmark]

It looks like there are two holes

Thanks. I retract my comment. Proof is in the pudding....good shot.

 

[racerone]

Post #11 is now clear with pictures.------You may be looking at a flaw in the casting.----Perhaps bolt hole was drilled 1/8" to deep ?

 

[jm_middleton]

Just want to thank all that replied. I used the small camera I ordered to inspect the inside of the engine. I couldn't find any broken pieces or fragments in the engine. I really think this is a flaw from the bolt hole. I took it out Sunday and drove maybe 10 miles and had no issues. I checked the area after running it all day and no oil had came from the hole.