Boat storage for winter. Lower unit oil.

[Dave Lehnert]

I have a pontoon boat I purchased used and this is my first winter for storage and maintenance. engine is a 1999 Mercury 50hp. 2 cycle.

First I want to replace the lower unit oil. my Seloc repair manual says to use. Quicksilver SAE 85-90. All I see online and in stores is 80-90 or High performance 90w oil. The 90w says not to mix with other gear oil.
http://www.quicksilver-products.com/water/outboard/lower-unit/

What else do I need to do that I don't know about??????

How about covering the motor with a tarp, good/Bad??????

Going to do plugs and water pump etc next spring. Looking at what I must do before freezing temps set in.

[Frederick Skelly]

Dave,
Does your owners manual say you need to store it with the lower shaft "wet"? Its been a while, but I always stored my outboard dry. Ran it out of gas and then drained the lower shaft of its lubricant. Then I put the shaft's drain plug back in, covered the engine and boat and called it good.

I never had a lick of trouble with the engine doing it that way.

FWIW,
Fred

[Dave Lehnert]

Dave,
Does your owners manual say you need to store it with the lower shaft "wet"? Its been a while, but I always stored my outboard dry. Ran it out of gas and then drained the lower shaft of its lubricant. Then I put the shaft's drain plug back in, covered the engine and boat and called it good.

I never had a lick of trouble with the engine doing it that way.

FWIW,
Fred


Don't say one way or the other. Just how to replace.

[Stephen Cherry]

Was that a made in USA or made in Japan Mercury?

One thing about outboards is that the covers do a pretty good job of protecting the engines. (cover with a tarp though for UV) If it can keep it dry enough to run while on the water, sitting on the trailer is pretty easy. One thing that I would do is eliminate every drop of ethanol fuel from the motor. This stuff wreaks havoc on these older motors. If you can, drain the carb bowls. A little shot of oil in each spark plug hole and a spin of the crank, and you are ready to go.

That said, on my motors, I usually take the carbs apart in the spring and clean them out with gumout. I have used yamaha engines for a while, so I can do those carbs in no time. One addition that I like is the canister type fuel filter-separators. Also, in the spring, check all of the fuel hose, and fittings. Only use the merc fuel fittings to the engine. The ones at the discount boat stores are JUNK and will leave you paddling.

Take the battery out and charge it every once in a while.

For the oil, is there a good merc dealer in your area? I would ask them what to use.

[Dave Lehnert]

Was that a made in USA or made in Japan Mercury?

Not sure, how do I tell?

[Stephen Cherry]

The made in Japans say made in Japan on them. Merc re-badged Yamahas for some motors. I've had both, and they have all been OK. The USA Mercury two strokes were very strong motors, the Yamahas are known for their durability. That's not to say that the Mercurys were not durable, but the Yamahas were "third world" proven.

[Myk Rian]

Why not call your local Mercury dealer?
Run the gas out of it.

[Chris Damm]

Always change the gear lube. It cuts down on the chance of rust and you won't have to remember to do it in the spring. Running without lube is very expensive! I always use the Mercury Quicksilver brand and never have any problems. Covering with a tarp is a good idea.

[Steve Baumgartner]

I don't think that the difference between 85-90 and 80-90 or straight 90 will hurt anything. That's not a particularly large viscosity range. If you change the lower unit lube in the Fall, you can examine it to see if moisture has seeped into the lower unit during use (the oil will be white and foamy). Replacing the lube will prevent this moisture from corroding anything over the winter, and then you could wait until Spring to see whether seals need to be replaced.

I agree that a tarp cover is more to keep debris off than anything else. The motor is designed to be outdoors uncovered in use. If anything, the weaker sunlight during the Winter will cause less UV aging.

If your region requires ethanol in the gas, you should definitely run the engine out and/or drain the regular gas and run some TruFuel in there. Ethanol gas left over the winter will very likely gum up the carbs and require a careful cleaning/rebuild in the Spring.

[Myk Rian]

ANY gas will evaporate, and leave varnish. Not just ethanol gas.

[Stephen Cherry]

ANY gas will evaporate, and leave varnish. Not just ethanol gas.

That's true, but the ethonol gas leaves a particular type of goo that's hard to deal with. When I bought a new outboard a couple of years ago, I was warned about this very strongly.

[Bill Huber]

There has been a lot of good info here.

I had a 1979, 115 merc that I sold 6 years ago, had it for like 28 years. In the time I owned it I never ran it out of gas. I could be really wrong but the way I look at it if you run it out of gas on a 2 cycle then you just removed all the oil form the cylinders and to me that is asking for the rings to freeze to the cylinder wall. I never had a problem in the spring starting it up.

I put Heat in the gas tank every fall before I stored it for the winter and with the gas we have now you also need to add Sta-Bil to the tank. I also drained the lower unit and checked it for water and filled it back with new oil. I would also remove the prop and put grease on the shaft and push it back against the seal, I hate changing the lower unit seal on one piece lower units. I put a trickle charge on the battery.

Never run the motor without water in the cooling system, if not in the water use a garden hose adapter but never run it without water, it is really hard on the water pump.

[Frederick Skelly]

Depending on how high your boat/motor sits on the trailer, you can also lower the motor into a big garbage can and run it for a while.

[Dave Lehnert]

Made in the USA

[Bill Cunningham]

I was a member of the merc forum here (http://www.marineengine.com/boat-forum/forumdisplay.php?30-Mercury-Mariner-Outboard-Forum), Lots of info and friendly help.. Just like here
right up until I sold my moneyhole in the water..

[William Payer]

Dave,

The Quicksilver 80-90wt gearcase oil is for motors under 70 hp. It is the default choice for your motor.
Mercury always has you drain/refill lower units before storage. I believe this is for two reasons. If you leave the gear case empty there is always the risk that you may forget to fill it in the spring, and some feel allowing the seals to be out of an oil environment might lead to drying them out and (3) if the gear case is subjected to water as in driving rain, AND the fill plug seals leak water past them, water will be stopped by the oil behind the plugs. The latter is really pushing the circumstances, but I like the first reason as it keeps me from inadvertently doing something foolish in the spring.
As to other winterizing procedures, they should be spelled out in your owners manual. Stabilize the fuel in the tank ( preferably fresh fuel) top off the tank to minimize moisture accumulation from air inside, run engine with stabilized fuel and if carburated, disconnect fuel hose and run gas out of it while spraying fogging oil through carbs as it is dying out. If fuel injected, just run stabilized fuel till it is distributed in engine and shut off. (drain canister fuel filter if present) ( you don't want to drain the fuel from a fuel injected engine as the electric fuel pump has a greater chance of getting gummed up , needing replacement--on my 150 EFI thats over $700 for the pump alone!) With either engine, pull plugs ( while still warm) , spray a coubple of teaspoons of either 2 TCW3 two cycle oil or fogging oil in spark plug hole and rotate flywheel a couple of revolutions to disburse the oil evenly on the cylinder walls. replace plugs and you are done winterizing the motor. Keep motor vertical to ensure all water drains out of it and none accumulates during snow and rain.
Trailer. It is always a good idea to repack wheel bearings before winter. This ensures uncontaminated grease for the next season as well as gives you a chance to inspect the bearings and hubs and make sure there is not water in them.
Cover the rig, making sure to allow for some ventilation. A solid waterproof tarp will accumulate quite a bit of moisture under it which a not good for your boat.
I hope I haven't been too long winded. Best of Luck.

[Dave Lehnert]

Thanks for all the tips.
I pulled the cover off the boat tonight and the seats were mildewed. So whats the trick keeping mildew out but boat covered?

[William Payer]

erc
Thanks for all the tips.
I pulled the cover off the boat tonight and the seats were mildewed. So whats the trick keeping mildew out but boat covered?

First, you need air circulating and exchanging with outside air. "breathers" (vents) are available to place over small holes cut in your tarp. You can also fabricate your own. First cut a small 1-2inch hole somewhere near the topmost of your tarp. Using additional plastic (or tarp material) cut a triangular piece large enough to cover the hole by about 3-4 inches in all directions. Tape this triangular piece over the hole "sqeezing" the sides inward before taping to form a triangular hood over the hole . It will now be able to shed rain water, yet keeps the air flow open. You need to put 3-4 of these on a typical boat to get good air flow. Air will be taken in at the bottom of the tarp and flow upward and out through the vents, allowing moisture laden air to be exhausted.
Commercial desiccant bags (or tub like containers) are available ( boating stores/web sites) to further ensure moisture is controlled. The bags are suspended under the tarp while the tubs are just set on the floor of the boat. They often do not even need to be used if there is good ventilation, but they are an additional weapon against moisture,

Edit note--------In the engine winterizing post above. If your motor is an EFI motor you can use fogging oil in the spark plug hole to coat cylinders. If your motor is a DFI (Direct Fuel Injection --like Optimax) NEVER USE FOGGING OIL IN THE CYLINDERS!!! The fuel injectors in a DFI motor are located with their orifice inside the combustion chamber. The orifice is very small. So small that the thick fogging oil can actually clog them leading to much trouble including total engine failure.