3.0 Merc Manifold port Plug On top of Manifold?

[JWebber]

Whats this plug for, that is on the back side on manifold towards the transom side? Whats this plug for and hole? Is it there for testing water temps or for inspection? and if so could one run a temp sensor there to monitor manifold temps??

See pic!

 

[Bondo]

Re: 3.0 Merc Manifold port Plug On top of Manifold?

Ayuh,... I believe it's a coreplug,...
If so, there ain't no threads in the manifold fer anything else...

 

[JWebber]

Re: 3.0 Merc Manifold port Plug On top of Manifold?

There are threads and the plug is screwed into the thread hole on the manifold, it's not a pressed in freeze plug type plug. Thats why I was asking, you can unscrew the plug and I guess look into manifold chamber, I would assume it's the water passage side and not exhaust or intake.

 

[Bt Doctur]

Re: 3.0 Merc Manifold port Plug On top of Manifold?

another gauge you dont need, with proper maintenance , and keeping 1 eye on the gauges you`ll do just fine.

 

[Bondo]

Re: 3.0 Merc Manifold port Plug On top of Manifold?

There are threads and the plug is screwed into the thread hole on the manifold, it's not a pressed in freeze plug type plug. Thats why I was asking, you can unscrew the plug and I guess look into manifold chamber, I would assume it's the water passage side and not exhaust or intake.

Ayuh,... Maybe a hotwater port for a heater,..??

 

[fibersport]

Re: 3.0 Merc Manifold port Plug On top of Manifold?

Could it be for a fresh water cooling system inlet or outlet?

 

[Bt Doctur]

Re: 3.0 Merc Manifold port Plug On top of Manifold?

Most likely it is the same threaded core plug found on risers and manifolds. there found on the top and bottom of manifolds.