mercruiser 140 closed cooling system problem missing plug????

[jammer28]

I just purchased this boat and don't have any books on it.... when I fired up the merc 140 water was pouring out the bottom of this cooling system...I felt underneath and there is a hole where I think a plug goes... if that is correct what should I put in there? size bolt and thread type... thanx... I have included a picture of my cooling system on this motor...

 

[Bt Doctur]

Re: mercruiser 140 closed cooling system problem missing plug????

Post the serial number to get a link to the correct manual,.
There are 2 plugs on the underside. The closest one aft is the raw water side of the heat exchanger.The other one if the A/F side of the cooling system. Both plugs are 1/8 pipe thread.

 

[Don S]

Re: mercruiser 140 closed cooling system problem missing plug????

Looks like an old 470 motor with a 3" heat exchanger to me, not a 140.

 

[achris]

Re: mercruiser 140 closed cooling system problem missing plug????

Looks like an old 470 motor with a 3" heat exchanger to me, not a 140.

Good call Don.... Starter on the port side... Definitely a 470....

Chris..........

 

[jammer28]

Re: mercruiser 140 closed cooling system problem missing plug????

hmmm ok I wasn't sure Don what size do you think that plug is?

 

[Don S]

Re: mercruiser 140 closed cooling system problem missing plug????

It's either 1/8" or 1/4" NPT.

 

[jammer28]

Re: mercruiser 140 closed cooling system problem missing plug????

thanx don I will pick up both tomorrow... let you know...

 

[jammer28]

Re: mercruiser 140 closed cooling system problem missing plug????

it was 1/4" thanx a lot for everyone's help....:joyous: