Winterizing your Mercruiser

[kirkll]

I know this subject is a bit premature for the time of year it is, but being a new boat owner, and never having had to maintain an inboard motor, I’m just looking ahead a bit and doing some research.

I'm in wester Oregon , just south of Portland. So we rarely get seriously cold winters. But every now and then we do get a couple weeks of seriously cold weather staying in the twenties, so I thought I’d look into the procedures to protect my boat engine from freezing up.

reading the sticky post on winterizing these contraptions is seriously intimidating for anyone not really inclined to tearing their outdrive off and pulling half the motor apart draining the water out.

when I purchased this old boat, I had nothing against studying up on the maintenance and rolling up my sleeves to a certain extent. But I really do not have any serious ambitions to become a marine mechanic at 65 years of age.

with that being said.... there have got to be other options for keeping these things from freezing up in winter besides tearing things apart, completely draining the system, and using antifreeze. Especially when I plan on using this boat 9-10 months out of the year for fishing. December, January & February is my only down time, and often I’m out fishing again in late February.

I lived in Alaska years ago and we had circulating block heaters that worked very well on a closed system on auto engines. But these raw water cooling systems are different.

Im sure I’m not the only one that still has concerns about winterization , that really isn’t up to pulling an outdrive every year.

what other options besides living in Florida are there?

 

[TunaFish389]

I have had my boat (Mercuiser 3.0 alpha one gen 1) for three winters now and it has sat outside getting below zero.

Last run of the season i use Iso-Heet Fuel Line Antifreeze in the tank and run it to under half tank. I then get four gallons of lowest temp RV water line antifreeze i can get. Warm up boat on hose and ear muffs. I made a rig that has a short piece of hose that screws into the muffs and other end has a cut open gallon jug (acts like a funnel) taped to it.

Once the engine is warmed up turn off, hook up the rig, start engine and dump the four gallons of RV antifreeze into the rigs jug. This will circulate the antifreeze through the system. I havent had issues but know you do at your own risk.

Other than that, cleaning boat and spray down engine with WD40. Dropping trailer on tongue and low drive as far down as i can. Remove batteries.

Only thing i do after winter is put batteries back and add fresh gas (why i store less than half tank).

 

[Furbird]

It's rare, but it freezes in Florida too.

I know this isn't an option for most folks, but I plan on keeping mine in the shop. My shop is insulated and climate controlled. Maybe a powerblanket would be an option for you? Pretty sure the link won't work but you can google it.

https://www.northerntool.com/shop/tools/product_200379472_200379472

 

[Bt Doctur]

simply removing the drain plugs and probing the opening to insure draining is usually sufficient. The muff method will also work IF YOU DRAIN EVERYHING FIRST O

 

[nola mike]

I have had my boat (Mercuiser 3.0 alpha one gen 1) for three winters now and it has sat outside getting below zero.

Last run of the season i use Iso-Heet Fuel Line Antifreeze in the tank and run it to under half tank. I then get four gallons of lowest temp RV water line antifreeze i can get. Warm up boat on hose and ear muffs. I made a rig that has a short piece of hose that screws into the muffs and other end has a cut open gallon jug (acts like a funnel) taped to it.

Once the engine is warmed up turn off, hook up the rig, start engine and dump the four gallons of RV antifreeze into the rigs jug. This will circulate the antifreeze through the system. I havent had issues but know you do at your own risk.

Other than that, cleaning boat and spray down engine with WD40. Dropping trailer on tongue and low drive as far down as i can. Remove batteries.

Only thing i do after winter is put batteries back and add fresh gas (why i store less than half tank).

This is the advice that leads to all the cracked block threads in the spring. Do it right, drain the block. Pulling the outdrive isn't for winterization, but it's annual maintenance. You don't need antifreeze if you drain the block. Otherwise get an outboard or pay someone to winterize it for you. Whole process shouldn't take more than 30 minutes, including pulling the drive.

 

[Rick Stephens]

I’m same age, and it takes me all of a half hour to winterize. And I do it several times in the fall as night time temps drop. I pull drain plugs, probe em, then pull the big hose off the water pump. Motor is now dry. I just lower the outdrive and make sure all the drain holes actually drain, until my final winterizing when I pull the drive off and stick on a rolling stand, where I can drain, inspect, refill and grease. I always pull the prop so I know it doesn’t have fishing line on it.

I’ll tell you what, my half hour will save me hundreds in maintenance and repairs if I shortchange that at all.

 

[Scott Danforth]

first, if you dont like maintenance, stop boating. boating is the most expensive, maintenance intensive hobby there is other than owning an airplane

second, you have to pull the drive every year if you winterize or not...... its preventative maintenance to inspect and adjust to not have things get way too costly. if you understand righty-tighty and dont poke your eye out with the screw driver and you can read the manual, its easy. much easier than you think it is.

third, to winterize, including pulling the drive, inspecting the gimble bearing, u-joints and bellows is a 1/2hour to a 2-hour max project.

I boat year-round in florida other than when its raining. I still pull the drive every year for the annual maintenance. and if the forecast is for cold weather, I pull the manifold drains and call it a day.

 

[Lou C]

there is no shortcut. Either you drain and poke the drains when freezing weather is on the way or worry about a cracked block in the spring. Either you R+R the outdrive like you are supposed to or suffer the consequences if the bellows leaks (ruined gimble bearing and u joints, or the drive won't even come off). I am going to turn 65 myself in the fall and have been doing all this myself approx 15 years worth.
If you REALLY want low maintenance the answer is very simple, do NOT EVER buy another I/O boat again, this is why many people will have nothing but an outboard. For my next boat that's what I'm doing. I love small block Chevrolets but I'd prefer to have mine in a hot rod, instead of a boat. Smaller boats outboard all the way. You tilt it down, it drains. Period! Owning one I/O boat here in salt water was enough for me to learn this lesson, I certainly don't need to repeat the experience. Yes outboards are expensive, yes the parts are expensive, you want to save $$ with an I/O then you gotta do the work. Next time I'll pay the cost of the outboard....and enjoy at least 15 years worth of low maintenance boating...

 

[Lou C]

this, every year...keeps it running well...

 

[tpenfield]

I'm only 64 years old . . . draining water from an engine and doing the fogging oil thing is hardly tearing it apart . I do think you should winterize if you are not going to be using the boat for the winter.

 

[kirkll]

Well just pulling the drive sounds like pretty simple stuff to all you boat mechanics, but I’m a retired carpenter, not a boat mechanic. Pulling things apart are no problem for me. It’s getting things back together again is where I usually run into problems....

draining the block doesn’t seem too intimidating, and I’m no lazy arse. And.... I ain’t afraid to get my hands dirty either. I’ve worked construction my whole life, and patched my vehicles back together for years. Soooooo I suppose if we are going to keep this rig in good shape and use it a lot, I better get used to the idea of pulling the out drive.

i have no idea how long this boat went without proper maintenance when I bought it last spring, but by the look of the impellers in the lower unit, I’m thinking a long time. I’ve got the boat in the shop right now having a bellows kit , gimble bearings, and lower shift cable replaced. Having no idea how long it had been since that was done , so I thought having the shop do it the first time should break everything loose, so pulling the drive myself won’t turn into a nightmare.

ive been working on getting this old girl back in shape off and on all summer. It’s a pretty cool old boat with a sound hull. So we think it’s worth putting the time and money into it. The motor was replaced right before we bought it and it’s in good shape. The whole wiring pack for the batteries needed replacement as well as a few other odds and ends. I rather enjoy working on it. I just don’t want to get in over my head too quickly. I appreciate you guys helping me out here.

how heavy are those outdrives keeping the lower unit attached? I like the looks of those wheelie carts I see a lot for pulling the out drive. I should probably look into buying one, or building something with a floor jack. Doesn’t look like something I’d like to try and muscle. Thanks, Kirk

for those curious about what I’ve got here. Here is a link to my project boat.

https://photos.app.goo.gl/635Vakqi3yPpdRGJA

 

[eric102]

how heavy are those outdrives keeping the lower unit attached? I like the looks of those wheelie carts I see a lot for pulling the out drive. I should probably look into buying one, or building something with a floor jack. Doesn’t look like something I’d like to try and muscle.

I made one out of some scrap lumber and a couple cheap Harbor Freight furniture dollys and use the trailer tounge jack to adjust the height of the stearn.

 

[tpenfield]

Looks like you got a 1990 Mercruiser Alpha One. . . . The outdrive probably weighs about 140 lbs. Many of us have built outdrive stands out of a moving dolly and a few sticks of wood.

I have 2 Bravo outdrives on my boat and they weight about 170lbs each. I got tired of lifting them a few years ago and built these things . . .


.

.
Since your area does not get way into the freezing temperatures, you could just drain the engine block and manifolds, then run about 6 gallons of the pink RV/Marine AF in through the outdrive and call it good. Keep the outdrive down so it does not trap water.

In preparation for the season, do a quick pull of the outdrive, grease the u-joints and gimbal bearing, and put it back together.

 

[Scott Danforth]

your best friend will be the stickies at the tops of the forums.

Here is the mercruiser section https://forums.iboats.com/forum/eng...miscellaneous-mercruiser-information?t=329915

most importantly, here is a link to the videos on pulling a drive https://forums.iboats.com/forum/eng...gines-outdrives/604924-a-couple-of-new-videos

 

[JASinIL2006]

Pulling the drive is really very easy and quick, and if you can handle a socket wrench, you can do it. Building a stand for the drive make it easier, and takes 30 minutes (less since you're a carpenter). You can check out achris's video on pulling the drive. You'll see that there is nothing to it.

Draining the block is the only way I'd try to protect my engine. Trying to suck up antifreeze via muffs is a recipe for a ruined engine. It is not hard to drain the block; the worst part are the gymnastics required to reach the plugs and, if you have a power steering cooler, to pull the hose off it. On my boat, getting at the PS cooler to remove the hose was the worst part of winterizing, so I installed a drain valve in that hose, so I no longer need to remove the hose completely.

You also need to get water out of the large hose connected to the circulating pump. If I had to drain that multiple times a year, I'd replace that hose, too, with one equipped with a drain. That would be simpler than unclamping and pulling the hose every time you need to drain.

 

[Furbird]

Another thought, for those of you that drain the block, have you ever thought of using a shop vac as a redundant check? I used a shop vac to drain all the coolant out of my LT1 in my Firebird when I did the water pump (water pump replacement is notorious for taking out the optispark, which is the distributor, because it is mounted below the water pump) and it seems to be that would be an easy way to be absolutely certain you have zero water in your block.

 

[kirkll]

Well I sure appreciate all the help and suggestions. I like that idea of putting drain petcocks in those hard to remove hoses idea, but finding the right sizes without restricting the flow concerns me.

like I posted earlier. I have this in the shop right now having a bellows kit installed and replacing the lower shift cable why they are at it. This should break everything loose making a yearly inspection easier when I pull this for the first time next year. It rather makes sense to pull the drive at the same time you winterize it. I mean you are already into the grease, why not?

im also getting the fuel pump changed out and a water fuel separates installed. The owner of the shop was bad mouthing my motor saying it looked like an auto block instead of marine. Says it has steel soft plugs...... but... it’s still set up with a oil pressure sensor to run the fuel pump.

Now considering that I typically trailer this after each days use, and my salt water exposure is limited to one weeks moorage, and about 20 hours run time each fall. As long as I flush it with fresh water after my trips to the coast, I don’t see those steel soft plugs as being a huge issue. Do you guys?

question: Are there any other serious concerns with the block being an auto block instead of a marine grade? The more I find out about this engine replacement, the more I think I got hosed down by the guy that sold it to me.

what are your thoughts on this? Kirk

 

[tpenfield]

Nothing special about a marine engine block, except the core plugs (brass) and the head gasket (stainless steel). So, if you have an automotive block, those would be the differences . . . which is not an easy fix after the fact.

 

[Scott Danforth]

since the marine motors come down the same assembly line at GM's Tonawanda engine plant as the trucks, yes, they look alike as the blocks are the same, the heads are the same, the rotating assemblies are the same, and the manual transmission flywheel from a truck is what is in the boat.

some of the later blocks came with stainless core plugs vs brass

 

[Rick Stephens]

Automotive use galvanized steel core plugs, and water pumps designed to run with antifreeze, will not last at all in fresh water, let alone brine. They rust out seemingly overnight. It is amazing how fast. All of us have seen different materials used for plugs in marine rated motors, it doesn't have to be brass. If your mechanic is right and you have the standard galvi plugs, they will let you know soon enough how come the use of other materials is so common.

As noted, nothing wrong about using an automotive block in a boat. It just needs to be modified to hold up to fresh water cooling. There are also other parts that have a little different spec for marine use - the camshaft is one. The torque range for a boat is similar to a pickup, so a pickup cam works great. Very different from the cam used in cars which tend to run at higher RPM with narrower power curve. Stainless steel head gaskets have become more common in automotive use, unlike the old days when automotive gaskets were prone to rusting out as well with fresh water cooling.

So I agree with your mechanic that it is important what core plugs are in your motor. Some of them require a lot of disassembly to access and one or two can even require a motor pull. Which isn't a big deal but is a PITA.