Access to Frost Plug 140

[Rick-101]

Hello everyone, I'm new to posting but have been reading for some time now.

I bought a Benito 18'' open deck with a merc 140 i/o sterndrive from 1986 last fall. (what we would call a "project")

When I winterized the boat, pouring anti-freeze into the cooling tubes attached to the thermostat. The exhaust manifold would fill, but the sideways U tubing leading into the block would just pour out the back off to the left side of the engine from what i believe to be the bell housing.

I purchased the Mercruiser manual over the winter and looked up the cooling system routing and some engine rebuilds on youtube. I am lead to believe that in the best of scenario its a frost plug and that the previous owners (a whole story in itself) did not properly winterize it.

Is it possible to access the frost plug by removing the bell housing, while the engine remains in the boat???
I have some but not much space from the transom (i there is a "standard" amount of space like any other stern drive 140)

The engine runs well, I did not run it very long as the impeller was not pumping water into the engine from the muffs.

Thank you for the help and this forum is a wonderfully rich source of information!

If you are curios here is a list of things that were wrong with the boat:
-finished fuel pump was removed and put back(?)
-Stearn drive was put back in without being in forward(it wouldn't go into gear without stalling)
-Hydrolic lift would was full of air and out of oil with dirty contacts.
-Brand new battery still half in wrapping was finished (drained and froze prob).
-Original rod from hydrolic to foot was lost and replaced with a makeshift rod
-Bilge pump is dead
-Everything was slapped back together with bright blue gasket sealant( at least i know where to start with the repairs! )

 

[Don S]

Re: Access to Frost Plug 140

Is it possible to access the frost plug by removing the bell housing, while the engine remains in the boat???

You can leave the engine inside the boat, but it will have to come out of the engine compartment.
The bell housing (Flywheel housing) is also the rear motor mounts, and they hold up the back of the engine. You not only have to remove the bell housing, but you also have to remove the coupler and flywheel to access the core plugs.

 

[Rick-101]

UPDATE Re: Access to Frost Plug 140

UPDATE Re: Access to Frost Plug 140

UPDATE

So buddy and I pulled the engine yesterday.

Removed bell housing and removed the flywheel. Frost plug definitely poped out, found it at the bottom of the bell rusted.

We flushed the water jacket(?) with the garden hoses, collected about 6-10 teaspoons of metal rush flakes at the bottom a magnet helped a lot. How bad is this structurally considering the age of the engine?

I'll make sure there is no water in oil too.


In addition, in the upper of the alpha one, the gear collar was snapped right off bellow the horizontal gear.
Would you recommend OEM replacement or Jobber, from what i see they range from 160-240$?

 

[Fishermark]

Re: UPDATE Re: Access to Frost Plug 140

Re: UPDATE Re: Access to Frost Plug 140

So.... you bought a boat with an engine that is freeze damaged and an outdrive that has broken gears? I don't mean to be negative, but before you spend any money at all fixing this up, you will want to see what else is bad.

Core plugs (AKA "freeze plugs") don't just fall out. When an engine freezes, it cracks 99 percent of the time. (I am guessing at the percentage, but I saw somewhere that 76.5% of all statistics are made up anyway. ). You are probably looking at a new replacement engine and outdrive. That's before you start with the hull - the transom stringers, etc.

 

[Rick-101]

Re: Access to Frost Plug 140

Though i should thank you guys for the help,
We pulled the engine, took off the head and looked over the block, no cracks and she looked to have very few hours on her. I seem to have had the luck of the 1% with me, at least that was on our side. Replaced the plug, changed the oil and bought a used foot. Got the engine running, she sounded good and had good compression.

First water trial, she ran very well and was pretty fast. Got back to the dock noticed a leak from the the I/O. lower half of the transom was rotten in the through hull region.
Redid the transom over the summer before returning to university, thanks to the help and videos of the guys in the restoration section of the forum.
Changed my bellows, gimbal bearing which was on its way out but did not manage to change the shift cable itself which i will do this season nor replace the trim limiters which had been cut off by the previous owner :facepalm: and only arrived by mail a month later after assembly.
Finally got the engine back in, all i need to do is get the batteries wired up and finish up the interior.
I'll be installing audible alarm for oil psi and temperature thanks to Don's writeup!

Thank you again, let me know if you have any concerns i might not of though of.

 

[Grub54891]

Re: Access to Frost Plug 140

Sounds exactly like mine,1985 larson bowrider.140 mercruiser. All freeze plugs popped,replaced and runs like a champ. Only paid $200.00 for it,and the upper drive was blown. It came with a spare drive so that was an easy swap. New bellows,ext. in process of full restoration as we speak!

Not same boat but same motor,I'm happy with the preformance it had this last summer. Thats why I'm rebuilding the girl!