Mercury 650 70’s outboard

[donny b]

I apologize if this is posted in the wrong spot. I was working on the motor and noticed this small hole that weeps water. Is that normal ? It’s aprox a 1976 merc 650. The part number is 19-73336 and I’m wondering if I need to replace it.

 

[Chris1956]

Not sure exactly what part is leaking. Likely the exhaust cover. They pit on the inside until one of the pits leaks.

If so, it may leak in other places eventually. However, at this time, the motor only has one leak and it is a million years old.

Let her dry and put a dab of silicone on it to seal it. If you want to be a big dog, use some black silicone. If she starts to leak in other places you may want to do something. I would source and price the cover. It may be NLA.

 

[Dave1027]

Is that a freeze plug on the side of the block that's leaking?

 

[donny b]

Not sure exactly what part is leaking. Likely the exhaust cover. They pit on the inside until one of the pits leaks.

If so, it may leak in other places eventually. However, at this time, the motor only has one leak and it is a million years old.

Let her dry and put a dab of silicone on it to seal it. If you want to be a big dog, use some black silicone. If she starts to leak in other places you may want to do something. I would source and price the cover. It may be NLA.

Guess I’m wondering if it’s normal. The part I point to in the video. When I look the part up it seems to have a small hole in the center.

 

[donny b]

Is that a freeze plug on the side of the block that's leaking?

This is the part up close. I ordered a couple from eBay just in case but wasn’t sure if it’s normal. When I rev the engine I noticed it spurt out of the hole too.

 

[racerone]

There is a vent hole in some covers.----It allows the poppit diaphragm to move.----If water leaks out ,the diaphragm has a hole or is not sealed properly.

 

[donny b]

There is a vent hole in some covers.----It allows the poppit diaphragm to move.----If water leaks out ,the diaphragm has a hole or is not sealed properly.

What do you suggest I do ?

 

[racerone]

Take the covers off.---Inspect parts.------Replace diaphragm and gaskets for the covers.

 

[Chris1956]

You can replace the poppit and see if that fixes it.

Be real careful removing the screws that hold the exhaust cover. They can break. A freshwater motor gives you a chance to pull the bolts with little breakage, but try to loosen them with a hand impact driver.

If it were me, I would run her at different speeds in the water and see how much leaks. If leakage is minimal, I would leave it be.

 

[racerone]

???-----Poppit valve must open at higher throttle settings.----These 3 cylinder motors have enuff cooling issues already.----Do not ignore a leak there !

 

[donny b]

This doesn’t seem like a job for a newbie like myself. I found the gasket parts on Crowley.

 

[racerone]

Just nuts and bolts.

 

[donny b]

Know if any good places to get more info on the repair ?