mercruiser 120 exhaust manifold petcock

[mercruiser user]

Just replaced water pump in drive unit, brandnew to boats, I opened the petcock in the bottom of the exhaust manifold and a good stream of water was coming out while engine was running, then it stopped after awhile, is water supposed to come out this or did it get plugged up.

 

[achris]

Re: mercruiser 120 exhaust manifold petcock

Welcome to iBoats.

Sounds like it got plugged up, but you shouldn't be opening that while the engine is running anyway. It's for draining the manifold and elbow for winterizing.

If you need to free it up, just poke it with a bit of wire or a long nail...

Chris......

 

[mercs4mark]

Re: mercruiser 120 exhaust manifold petcock

Just replaced water pump in drive unit, brandnew to boats, I opened the petcock in the bottom of the exhaust manifold and a good stream of water was coming out while engine was running, then it stopped after awhile, is water supposed to come out this or did it get plugged up.

Stick a small screw driver up in the petcock ...they do get clogged up with sediment and sand, be sure to do this at fall when you winterized the boat also to be sure all the water is out of the manifold. Do it to the one on the side of the block also.

 

[ENSIGN]

Re: mercruiser 120 exhaust manifold petcock

It may have gotten plugged up. Verify that you still have water coming from the outdrive by removing the water inlet hose at the thermostat housing and briefly starting the engine.

 

[mercruiser user]

Re: mercruiser 120 exhaust manifold petcock

Welcome to iBoats.

Sounds like it got plugged up, but you shouldn't be opening that while the engine is running anyway. It's for draining the manifold and elbow for winterizing.

If you need to free it up, just poke it with a bit of wire or a long nail...

Chris......

ok thanks for responding, now I know for sure