240 mercury water coming in while running

[HeavyHanded]

Here’s the video...boat runs perfect but in the back part of motor under the heads, water leaking in but only while running?

 

[HeavyHanded]

Bump

 

[dblackstone]

My best guess would be you need to replace the pump gasket

 

[Tim75]

Others have had this issue here. Some had the gasket fail. Some one had the adapter casting corrode thru.

Either way, you need to pull the engine.

 

[HeavyHanded]

My best guess would be you need to replace the pump gasket

Thanks! Kinda what I thought but odd that it doesn’t leak except under power.

 

[HeavyHanded]

Others have had this issue here. Some had the gasket fail. Some one had the adapter casting corrode thru.

Either way, you need to pull the engine.

Thank you! Ideas on best place to source parts for the merc 240 parts?

 

[Tim75]

Ebay for some parts. Crowley marine, BamMarine are a couple. Most Merc dealers can get parts. But some have been discontinued by Merc. The dreaded NLA in the catalogs (No Longer Avail.)

You only get water when the engine is running because that is cooling water. Only flows when ... the engine is running. The impeller is your pump.