2 Cycle Outboard Oil in a Gas engine for Winterize?

colo-pr

Member
Jun 17, 2019
63
Boat Info
2006 Sea Ray 200 Sundeck. 2019 RAM 1500 and 2014 Jeep Grand Cherokee
Engines
Mercury EFI 5.0 v8
Hi guys,

I'm getting prepared ahead of time to do the yearly maintenance/winterize of my Sundeck 200 2006 when we get close to the end of the season. Is the first time I am going to do it so I am getting all info and creating a checklist. I have 2 Service Manuals and I still not sure which one is the right one for my engine (Mercruiser 5.0 EFI). I have the Service Manual #24 and the #31. The pictures in the #31 looks more like my engine. Serial number of my engine is: 0W351348.

In the part I am stuck is the step of add 2 cycle oil to the gas system for "Long Storage/Cold Winter" because the Service Manual #24 says:

"b. Remove the water separating fuel filter.
c. Pour out a small amount of fuel into a suitable container, then add approximately 2
fluid ounces (60 ml) of Quicksilver 2-Cycle Outboard Oil to fuel in the water separating
fuel filter.
d. Reinstall water separating fuel filter."

bu the Service Manual #31 says:

"1. In a 23 l (6 U.S. gal.) remote fuel tank mix:
a. 19 l (5 U.S. gal) regular unleaded 87 octane (90 RON) gasoline
b. 1.89 l (2 U.S. qts.) Premium Plus 2-Cycle TC-W3 Outboard Oil
c. 150ml (5 ounces) Fuel System Treatment and Stabilizer or 30 ml (1 ounce) Fuel System
Treatment and Stabilizer Concentrate.
6. Start and operate the engine at 1300 rpm for 5 minutes."

So, as you can see one manual says to put a little bit and the other one to use a lot for a long period of time (5 minutes). Makes sense for me the step of the 2 cycle oil to prevent corrosion but I never heard about a gas/4cycle engine be running on 2 cycle mix for 5 minutes and that kinds of scares me.
Is not the same 2 ounces of oil than 2 qts, huge difference.

What do you do? or which manual I should follow? Can I damage a gas engine running on 2 cycle mix?
 
Same end result - you're fogging the engine. The fuel/water separator route will be a lot easier from a process standpoint.

I've personally never fogged my marine engines (or any others) and have never had a problem (knock on wood) even with our extended northern storage seasons. Change the fluids, fill the gas tanks, clean her up and relax - it's winter.

Of course there are two sides to this, like most things. It would be interesting to see a poll on CSR regarding who fogs and who does not. If I were a gambling man...which I'm not....I'd bet it's 80% do not fog, 20% do. A total, uninformed guess...
 
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Your not going to use 5 1/2 gallons of gas running for 5 min. Manual #24 makes more sense. Personally I use nothing for a 6 month layover

Makes sense, maybe the instructions in the Manual #31 are more towards a shop who has to winterize a ton of boats and that solution container will help them fine through the season but for just one boat definitely I am not going to use all of that solution in 5 mins, or something is very wrong with the motor and gas consumption haha
 
Same end result - you're fogging the engine. The fuel/water separator route will be a lot easier from a process standpoint.

I've personally never fogged my marine engines (or any others) and have never had a problem (knock on wood) even with our extended northern storage seasons. Change the fluids, fill the gas tanks, clean her up and relax - it's winter.

Of course there are two sides to this, like most things. It would be interesting to see a poll on CSR regarding who fogs and who does not. If I were a gambling man...which I'm not....I'd be it's 80% do not fog, 20% do. A total, uninformed guess...

That's another thing, I read in other places not to fill the gas tank because is more gas that is not going to be fresh next season regardless you use stabil or not, but this manual says keep it full. I wonder why keep it full because is not mix with oil, so whats the idea? actually, is more amount of ethanol=water in the tank? Why I want to keep it full during storage?
 
That's another thing, I read in other places not to fill the gas tank because is more gas that is not going to be fresh next season regardless you use stabil or not, but this manual says keep it full. I wonder why keep it full because is not mix with oil, so whats the idea? actually, is more amount of ethanol=water in the tank? Why I want to keep it full during storage?

I think it's hard to argue with full tanks of ethanol-free marine fuel. Like you said I think the "do not fill" argument is more around ethanol/water in the gas.

For the record - IT IS AUGUST!!!!!!!!!!!!!!!!!!!!!!!!!!!! We should not be having this conversation right now. Summer is short enough as it is. Please stop. :)
 
That's another thing, I read in other places not to fill the gas tank because is more gas that is not going to be fresh next season regardless you use stabil or not, but this manual says keep it full. I wonder why keep it full because is not mix with oil, so whats the idea? actually, is more amount of ethanol=water in the tank? Why I want to keep it full during storage?
Less air in the tank results in less condensation/water vapor from that air being pulled into the fuel.
 
actually, is more amount of ethanol=water in the tank? Why I want to keep it full during storage?


You ar going to hear at least two schools of thought. Filling the tanks with gasoline will displace any air and reduce the metal surface area that can condense and create moisture.
The flip side of that is to leave an empty tank, and reduce the amount of ethanol. Come spring, top the tsnks with fresh fuel diluting any old crap.

Personally, both have worked great for me, but I lean to having fresh gasoline.
 
For the record - IT IS AUGUST!!!!!!!!!!!!!!!!!!!!!!!!!!!! We should not be having this conversation right now. Summer is short enough as it is. Please stop. :)
Now this is a topic we should all agree on. Never use the "W" word in August.
 
I think it's hard to argue with full tanks of ethanol-free marine fuel. Like you said I think the "do not fill" argument is more around ethanol/water in the gas.

For the record - IT IS AUGUST!!!!!!!!!!!!!!!!!!!!!!!!!!!! We should not be having this conversation right now. Summer is short enough as it is. Please stop. :)

hahaha, is true, I think I brought it because I am very excited to work on my boat and I can't wait LOL.
 
You ar going to hear at least two schools of thought. Filling the tanks with gasoline will displace any air and reduce the metal surface area that can condense and create moisture.
The flip side of that is to leave an empty tank, and reduce the amount of ethanol. Come spring, top the tsnks with fresh fuel diluting any old crap.

Personally, both have worked great for me, but I lean to having fresh gasoline.


I also lean to the side of have fresh gas at the beginning of the next season. The interesting part is the argument of: "reduce the metal surface area" but hey, the gas tank in my boat is PLASTIC! Anyways, still interesting that the manufacturer leans to the side of leave them full because that's what they have in the manual.
 
I don’t fog but I do add a bottle of her favorite fuel stabilizer and take her for a WOT run to get it into carb before layup.

I also only use non ethanol gas.
 
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In the part I am stuck is the step of add 2 cycle oil to the gas system for "Long Storage/Cold Winter"

I never heard about a gas/4cycle engine be running on 2 cycle mix for 5 minutes and that kinds of scares me.
Can I damage a gas engine running on 2 cycle mix?

When I had a carbed engine, I always fogged, especially since it took a couple minutes to do so. With these MPI's, you can't just spray oil down the air intake, that's why you mix up a fuel cocktail. The mixture is pretty strong 10/1, so there's lots of oil in there. The idea is to get oil in the top end.
If you go this route, DON"T do 5 gallons. I used about a quart for 30 minutes of running a V6. So a gallon will do you. Nothing to be scared of, it's not going to hurt running this mixture.
The first time it was sort of a pain though, disconnect fuel line, and rig up a remote tank.
FWIW, have a couple buddies that do nothing but drain the water and park the boat. Never had issues, but not sure if I can go that route.

For fuel, I try to use non-E fuel for the last few outings of the year, and then just dump some stabil in there.
 

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