74 merc I/O - Where does this hose go??

[UGS]

Need help. Winterizing engine and want to get anti-frezze in all the right places.<br /><br />1974 140 hp GM 4 cyl merc I/O.<br /><br />Facing front of engine, there are two hoses that join at a value at top front of engine. hoses are radiator type hoses.<br /><br />To the right hose is about 1 1/4" dia. to the left about 3". smaller hose definitly is part of cooling system. Larger hose looks like it should be but am not sure. What is this hose for? and should anti-freeze be poured down this hose??<br /><br />thanks.

 

[rodbolt]

Re: 74 merc I/O - Where does this hose go??

the large hose is for the ciculating pump. the small hose coming from the transom is seawater to the engine and the other small hose is seawater out to the exhaust manifold. keep searching about and you will find many arguments on pouring AF in as opposed to draining the engine block and using a 5 gallon AF mix and using the seawater pump to refill the system with a NON -toxic AF mix.

 

[UGS]

Re: 74 merc I/O - Where does this hose go??

Thanks, bottom-line is if I put AF down this larger hose, it will not hurt anything. The question I take to be is the level of effectivness doing this versus draining and refilling.

 

[Don S]

Re: 74 merc I/O - Where does this hose go??

You MUST drain everything first. If you don't, there is nothing to fill because the water in the engine is already taking up the space, and that antifreeze is not going to magically mix with the water already in there.

 

[rodbolt]

Re: 74 merc I/O - Where does this hose go??

hahahaah<br /> here we have magic AF <br />at least until we get the odd front where we have 3 or more days in the single digits. then daddy and the horse get new shoes come spring. happens at least once evry 5 years or so, come spring 15-20 busted blocks

 

[UGS]

Re: 74 merc I/O - Where does this hose go??

OK, I have done the following for many years and, don't ask me why, this year I decided that I might have added protection by "flushing the engine with AF and then leaving it dry. <br /><br />Each year I opened and drained three areas;<br /><br />Port side of engine - Petcock center and lowest point of the three, in what looks like the block. About 6 or 7" above bottom of engine.<br /><br />Above petcock and toward front of engine a bit. Underside of what appears to be heat exchanger. a small hex head cap that goes into the body from underneath.<br /><br />Higher yet and toward the back of the engine. Another small hex head cap going into the body from the side (riser??)<br /><br />Have I missed a drain somewhere? I have not had issues previously, may be I'm just lucky or maybe I got them all.<br /><br />Where does the water that is in the area (larger hose) of the circulating pump go? I did pour AF down there and did not see anything drain.<br /><br />Appreciate the feedback.

 

[Laddies]

Re: 74 merc I/O - Where does this hose go??

Thats it on a 4 popper some take the large hose off the w/pump to