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1974 mercruiser 165- frost plugs?

7

77jester

New member
Short story- but the help would be really appreciated. 1974 Mercruiser 165 (gm 6 cyl)After the boat sat for 3 years- replaced the impeller- rebuilt the carb, new points- put it in a big bucket- starts right up, running smooth........ Water seems to be coming out of the block between 2 and 3 cylinder- almost looks like a small round hole?? 1/4 inch diameter? up under the exhaust manifold?? ( not the big frost plugs on the side) Really small hole up high?? I read an archive post that said that there may be some frost plugs up there?

can I pull the exhaust manifold ( that looks like a pain) and just JB weld the dang things since it's not much water??
 
Re: mercruiser 165- frost plugs?

Could be a core plug , have to remove the exaust manifold to see.Drain everything first, remove the riser, then remove the manifold
 
Re: mercruiser 165- frost plugs?

you mean the drain hole has no plug in it ? It's threaded? Maybe threads gone tap it and install a piece of brass pipe and a cap, i had to do that on my mani.

Oil stays good after running no milkshake ?
 
Re: mercruiser 165- frost plugs?

not in the exhaust manifold- coming out of the block- right where it seems to have a little roundness going into the head- about an inch down from the cylinertop/ head join area. Core plug??
 
Re: mercruiser 165- frost plugs?

Might be i don't think so. Like the BT said mani got to come off one way or the other.

Take a pic and post it here lets see what it is and see if we can save it.
 
Re: mercruiser 165- frost plugs?

thanks- manifold off......... :eek: I'll see what I can do- might be a few weeks till I jump back in- but I'll get to it
That giant manifold looks scary as hell- 6 bolts, a carb and linkage and giant exhaust hose??
 
Re: mercruiser 165- frost plugs?

loosen up the rubber hose, remove the mani with the riser and carb attached, disconnect the cable.

Shoot the bolt heads with pb blaster let sit keep doing it 3-4 times then get the center ones first. When you reinstall all you will need is a gasket and a little grease on the threads, some say to use other things if you want use grease or aviation form a gasket nothing else.

Make sure the mating surface is clean.

Also you can buy 2 extra long bolts cut the heads off and screw into the end holes and slip the gasket and mani over the bolts install the center ones and unscrew the extra long bolts and install the correct bolts with heads.

Understand.

It's easy you can do it.
 
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