cooling, raw water??????

[Arlie]

Hi I'm am new to this forum. I have been around boating my entire life and I'm very mechanically inclined. I recently picked up a 1973 hurricane fun Decker ( my first boat). It has a 188HP mercruiser (ford 302) with a 888 stern drive. I am completely new as to how this motor even operates. I placed muffs on the inlet ports for stern drive turned on hose and started engine, and engine runs fine for sitting for two years. my question is about the cooling. where are the exit ports for the water? does the water fill up the compartment below the engine where the oil pan sets and the bilge pump, pumps it out? or should the water be pulled in by the stern drive and pushed out by the engine somewhere? haven't gotten bilge pump working yet so water that is pushed into stern drive with hose fills space below engine and drains out the drain plug hole. am I on the right track or do I have a leak in my cooling system. any explanation or links would be greatly appreciated, like I said im complete noob have no idea. Thanks

 

[tpenfield]

Re: cooling, raw water??????

Welcome to iBoats . . .

Since you are very mechanically inclined, you will probably want to get the service manual for the engine/outdrive and browse through it.

Water runs through the engine and out of the outdrive . . . basically the lake or ocean is your radiator.. It should not fill up the bilge, as that is a bad thing . . .

Of course there are some closed cooling systems which add a twist to the raw water cooling process.

 

[Arlie]

Re: cooling, raw water??????

Thanks for such a fast response. I'm going to pick up service manuals this weekend, was guessing water shouldn't fill up bilge, but had no clue was just trying to get a head start. now I can try to identify leaking coolant part and take it in with me this weekend. Thanks.

 

[Dshow]

Re: cooling, raw water??????

Post the serial numbers for your engine and outdrive and I'm sure someone can provide a link where you can download the service manuals...

 

[Don S]

Re: cooling, raw water??????

You don't need a manual at this point. Start the engine up on muffs and just look at where the water is coming from. Take a couple of pictures so we can see what the problem is.

Would have to bet you have core plugs popped due to freezing.

There is nothing in the manual going to tell you that.

 

[Arlie]

Re: cooling, raw water??????

Thanks for the help. Engine# 3601224 Stern drive# 3607063. The winner is the freeze plugs.:clap2: Left side plug is missing, but manuals will still be helpful. I'm sure I have lots to do before she hits the water. Will plugs for a 1973 302 ford from the auto parts store fit or are they different for the marine version? Bilge and prop are next if replacing plug does not reveal any other problems.

 

[04fxdwgi]

Re: cooling, raw water??????

Thanks for the help.View attachment 196094 Engine# 3601224 Stern drive# 3607063. View attachment 196095The winner is the freeze plugs.:clap2: Left side plug is missing, but manuals will still be helpful. I'm sure I have lots to do before she hits the water. Will plugs for a 1973 302 ford from the auto parts store fit or are they different for the marine version? Bilge and prop are next if replacing plug does not reveal any other problems.

Marine are brass and std automotive are steel. Most suppliers should have both available.

 

[Arlie]

Re: cooling, raw water??????

Thanks a lot guys for taking time to answer my noobie questions. I will make sure to look for the brass ones.

 

[81 Checkmate]

Re: cooling, raw water??????

This is just me....but i would fix the core plug first and get it running with water hose on muffs and check for leaks....before spending any kind of money!

There is a reason the plug poped out.....Freezing water?

Motor could have a crack in it.

Good Luck!

 

[Don S]

Re: cooling, raw water??????

The winner is the freeze plugs.

They aren't "Freeze Plugs", they are core plugs. There is a very good chance that the block is cracked as well as the core plugs being popped out.

What you really need to do is get a temporary expansion plug and put in place of the core plug, then block off the exhaust system and the water inlet hose and pressurize the block to see if it holds pressure. If it's cracked internally, you will fill the crankcase full of water when running.

 

[Arlie]

Re: cooling, raw water??????

I'm picking up the core plugs tonight. I realize that block could be cracked and the core plug could be the first indicator of bigger problems. The oil at this point doesn't look to have water in it. ray2:I'm still hopeful, but i will fix core plug and try some pressure before doing anything else. Not trying to get to far ahead of my self, need to make sure she won't fill up with water before it needs to move. Any suggestion for what to plug exhaust with? I'll look around here to see if there is any threads relating to a pressure test. Thanks

 

[Arlie]

Re: cooling, raw water??????

Don't know what luck I stepped in but the core plugs are in and block appears to be ok! I let it idle for 20 mins ( 73 out side temp in the shade) is this enough to get to normal operating temp and let thermostats open? I only have light flow out the of prop (on muffs), so unsure if i'm looking for clogs or if I need to run longer. Thanks for the help.

 

[dubs283]

Re: cooling, raw water??????

Don't know what luck I stepped in but the core plugs are in and block appears to be ok!

guy i work with told me years ago he had a customer come in his shop with an early 70's vintage mercruiser ford that had milkshake oil

he found a turnbuckle wedged between a core plug and the stringer on one side of the motor

when he asked the customer about the turnbuckle the customer told him he was sick of re-installling the core plug every spring so the previous fall he wedged the turnbuckle in there - turns out the core plug falling out every winter had saved his block from getting cracked for years!!!

maybe there's something bout those older ford blocks that didn't crack when not winterized??

best of luck to ya!!!

 

[Arlie]

Re: cooling, raw water??????

Thanks for the story, awsome. Owned several mustang's ( 10 ) 4 had to have core plugs replaced none cracked. Partial to Ford lol. Again thanks for sharing.