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Hole in Water Pipe - 1975 Johnson 40hp

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AndrewRoth

New member
I have a Johnson 40E75C with a hole in the side of the water pump pipe, and I have no idea how it got there. It's obvious that the hole was punctured from the outside in as shown in this endoscope footage. But there is no way to access that portion of the pipe while in place. I thought maybe it was a rogue screwdriver coming in from the shift linkage connector port, but it's too high up in the leg to get at it.


Any ideas to what might have caused this?


I think I need to pull the powerhead to remove the pipe, is that correct?
 
That hole is a factory drilled hole. Its purpose is to have a water spray mixed with the hot exhaust being blown downward and sprayed in such a manner so that it cools the tuning tube and the inside of the long exhaust housing. If that hole was not there, the long exhaust housing (between the powerhead and the lower unit) would have its paint burn off on its first outing.
 
Thanks Joe!

That makes sense.

I though I may have stumbled onto the cause of my overheating issue, but it looks like some more investigating is needed.

Do you know if a blown gasket between the power head and housing can cause over heating?

Thanks again!
 
AndrewRoth said:
Do you know if a blown gasket between the power head and housing can cause over heating?
Click to expand...

That is always possible... it depends on just where the gasket is blown.

When it comes to blown gaskets... it's usually the head gasket that is blown and is allowing the combustion pressure to enter the water passageways area. This causes a stalemate causing the water to flow so far, then just to sit there and boil away.
 
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