Boat Motor Storage

[Middle-aged_Ball_Coach]

I don't have a boat, but I am a marine engine service engineer, and I have a little experience winterizing engines. It's been a while since I stayed at a Holiday Inn Express.

I'd recommend draining all the fuel except what will run the engine for a few minutes. Then add the stabilizer (I use double the recommended amount, but that's just me). Run the engine and "fog" it. You want a good coat of preservative on all the internal parts. Shut it down, and preferably drain as much fuel from the tank as you can, though if it has the stabilizer it should be OK for the winter.

Then the best thing would be to spray a VCI (volatile corrosion inhibitor) in the tank to prevent your worst enemy, rust. More is better. Even more is even better.

If it's in your climate controlled basement, that's the best case. Temperature swings will cause condensation in any engine... and this happens every night. If you run the engine everyday during the season, it's not a problem. But people don't realize even after a few nights/days of the temperature cycle, you can get an ugly coat of rust in your intake, cylinders, etc. We recommend running block heaters overnight to prevent the condensation, and if your boat's idle at the marina for longer than a week or two (i.e. you don't want to run block heater) then preserve the insides with VCI. That may sound extreme, but I deal primarily with salt water vessels so we've seen them all.

Oh, and for startup in the spring, just add fresh fuel.

Sorry I don't have a TL; DR version.

I want a neighbor like you. That's good information.

 

[Cyberbach]

I have an older ski-do and I was winterizing it a few years ago and as I always did I ran it with the gas turned off to clear the lines and fogged it with WD40 instead of the stuff I got from see do. Well... that didn't go so well, you see WD49 uses propane as a propellant so as I was throttling it up I tried to shut it off and it just races with all the propane I was blasting into the air intakes and just bangs the rev limiters, pow, pow, pow, pow, I'm freak'n out trying to pull plugs... quite the scene, filled the garage with smoke.

 

[Elwood von Kiowa]

I have an older ski-do and I was winterizing it a few years ago and as I always did I ran it with the gas turned off to clear the lines and fogged it with WD40 instead of the stuff I got from see do. Well... that didn't go so well, you see WD49 uses propane as a propellant so as I was throttling it up I tried to shut it off and it just races with all the propane I was blasting into the air intakes and just bangs the rev limiters, pow, pow, pow, pow, I'm freak'n out trying to pull plugs... quite the scene, filled the garage with smoke.

I laughed, but it's not funny when it happens to you!

BTW, that's why fogging doesn't work for Diesel engines -- they'll just run away (out of control) on the fogging oil.

 

[Cyberbach]

I've had several old Mercedes diesels and have the timing figured out to where I can kill the switch and the vacuum modulator engages just as I fog the intake and it pulls it through before it dies. But yea it was like that, I had pulled the key and it was "dieseling" out of control until the source was spent.

 

[FredsRedAxe]

Its when temps fall below the ability to hold the airs current moisture content, creating dew.
The moisture in your motor is vapor until it hits a cold surface, like a class of iced tea in summer
And by often, not alot of air gets into your motor, but it does, and with it its moisture/vapor.
The more often the vapor is replaced and the dew point is exceeded , the greater amount of water is condensing inside your motor.
It doesnt take much over time to cause problems

My question was regarding phrasing. Are you talking about surface temps or ambient temps? Because thats not my understanding of the dew point which is why I asked what 'often below" meant. Living in Phoenix we don't deal with this issue much but I thought that condensation results when ambient air temperature cools to the dew point temperature, not below it. This is the point of 100% saturation and the point where the air will lose moisture (condensation) and as that moisture is lost the dew point temp will drop. I'm just curious how ambient temp can be "below" the dew point when the relationship between the two technically shouldn't allow that to happen?

 

[Elwood von Kiowa]

My question was regarding phrasing. Are you talking about surface temps or ambient temps? Because thats not my understanding of the dew point which is why I asked what 'often below" meant. Living in Phoenix we don't deal with this issue much but I thought that condensation results when ambient air temperature cools to the dew point temperature, not below it. This is the point of 100% saturation and the point where the air will lose moisture (condensation) and as that moisture is lost the dew point temp will drop. I'm just curious how ambient temp can be "below" the dew point when the relationship between the two technically shouldn't allow that to happen?

Technically speaking, dewpoint is air temperature. However, if a solid surface (like your engine block) is below the dewpoint temperature, moisture will condense on the surface. That's why your house windows fog up on the inside in the winter (maybe not in Arizona but...), or why eyeglasses fog up when you come in from the cold.

So, if you can keep your engine temperature warmed above the dewpoint, moisture won't condense on/in the engine surfaces. Hence the recommendation to run your block heater in the summertime.

To answer your last question, once the air temperature drops to the dewpoint, dew will form (ok Mr. Obvious). The air can cool further, but that just means it's raining, foggy, etc. Technically then, the dewpoint will continue to drop with the air temp (air temp can't be below dewpoint).

 

[FredsRedAxe]

Technically speaking, dewpoint is air temperature. However, if a solid surface (like your engine block) is below the dewpoint temperature, moisture will condense on the surface. That's why your house windows fog up on the inside in the winter (maybe not in Arizona but...), or why eyeglasses fog up when you come in from the cold.

So, if you can keep your engine temperature warmed above the dewpoint, moisture won't condense on/in the engine surfaces. Hence the recommendation to run your block heater in the summertime.

To answer your last question, once the air temperature drops to the dewpoint, dew will form (ok Mr. Obvious). The air can cool further, but that just means it's raining, foggy, etc. Technically then, the dewpoint will continue to drop with the air temp (air temp can't be below dewpoint).

Thanks for reply. It has got to be a chore to keep anything maintained in humid, salty air climates. We're so spoiled here, maintaining things is largely just about keeping them out of the blazing sun. Both my outboards, Honda 9.9 and Mariner 2.2 have been trouble free for the years that I've had them. A couple of years ago I bought a small boat from a guy in San Diego that came with a little 2hp Honda. I ended throwing the motor in the trash because it had corroded so badly from that ocean air.

 

[NorthwoodHusker]

Thanks for reply. It has got to be a chore to keep anything maintained in humid, salty air climates. We're so spoiled here, maintaining things is largely just about keeping them out of the blazing sun. Both my outboards, Honda 9.9 and Mariner 2.2 have been trouble free for the years that I've had them. A couple of years ago I bought a small boat from a guy in San Diego that came with a little 2hp Honda. I ended throwing the motor in the trash because it had corroded so badly from that ocean air.

You only need something with enough mass to collect it.
Elwood nailed it.