How to winterize my outboard...

Josh

Dead in the water
Staff member
Admin
Weather report says it's not getting out of the 60's this week and we're starting to see some sprinkles. Looks like summer is done. I know there's some fall bass fishing to be had. But I suspect that I'm going to be wrapping up my lake fishing in the boat for the season pretty soon. Time to start thinking about rivers!

So what do I need to do to winterize my little 9.9 Yamaha 4 stroke? Is there anything in particular that will help me have a better time firing it up next spring? Also, I've got sta-bil in the fuel tank, but can it really sit all winter?
 

M_D

Top Notch Mediocre Flyfisher
Forum Supporter
Yer not gonna drag it down to the Skagit and try for some silvers? Heck....I'm still working to get mine in the water :)

I picked up one of these for my older 15 horse.....very helpful. I no longer spend hours looking for the flux capacitor when trying to diagnose the problem by myself. ;)
1662992546070.png

My manual devotes 2+ pages to storage/winterization....crazy thorough with maybe some overkill. Lemme know if yours is in this age bracket and I'll email some pix of the pages.

Mike d
 
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Josh

Dead in the water
Staff member
Admin
Lemme know if yours is in this age bracket and I'll email some pix of the pages.
Thanks for the offer! I'll double check, but I'm pretty sure mine is the previous generation and a 94-95'.
 

Evan B

Bobber Downey Jr.
Staff member
Admin
fill up a gas tank with non-ethanol fuel and some stabilizer. Run that in to your engine and you should be fine. Some guys go as far as "fogging" them and all that, but I don't really find that to be particularly necessary usually as long as you have good, clean fuel in it. Alternatively, you can also just unhook the fuel line and run it dry... but even then, I'd recommend getting good fuel in it before you do just to be sure you're not going to leave any ethanol fuel in there to gum up.
 

Russell

Steelhead
I have always just run all the fuel out of the engine in both my two and four strokes and have never had a problem the next spring. Prime them good and they fire right up.
 

mcswny

Legend
Forum Supporter
fill up a gas tank with non-ethanol fuel and some stabilizer. Run that in to your engine and you should be fine. Some guys go as far as "fogging" them and all that, but I don't really find that to be particularly necessary usually as long as you have good, clean fuel in it. Alternatively, you can also just unhook the fuel line and run it dry... but even then, I'd recommend getting good fuel in it before you do just to be sure you're not going to leave any ethanol fuel in there to gum up.

This is exactly what I do with motorcycles, and I'm sure it's all the same.
Our winters aren't as long as say--the east coast.
 

Josh

Dead in the water
Staff member
Admin
fill up a gas tank with non-ethanol fuel and some stabilizer.

To be clear, I do run non-ethanol gas in it as did the previous owner (or so he claimed, but he seemed legit).

I realize the sta-bil in the non-ethanol gas might be overkill, but I didn't think it would hurt to add it. You post seem to confirm that.
 

Evan B

Bobber Downey Jr.
Staff member
Admin
To be clear, I do run non-ethanol gas in it as did the previous owner (or so he claimed, but he seemed legit).

I realize the sta-bil in the non-ethanol gas might be overkill, but I didn't think it would hurt to add it. You post seem to confirm that.
Stabil does still help with non-ethanol. For the amount of time we're doing it, it's overkill, but it's a cheap insurance just in case it ends up sitting longer than you intended.
 

Josh

Dead in the water
Staff member
Admin
Winterize an outboard in September?

I fish every season.
Never have i winterized an outboard in 30+yrs.

Winterizing is for quitters.
Ha! Well, that's one way to think about it.

But this boat is a mostly bass vehicle for me. While you CAN fish for bass in the dead of winter, I use my cold season fishing time to head to the rivers. And the time I'm not doing that, it's time to slide on snow with the kids.

Anyway, with the weather holding up, I'll probably give it another few weeks.
 

Matt B

RAMONES
Forum Supporter
Anyway, with the weather holding up, I'll probably give it another few weeks.
I figure I’ll get mine up and running nicely right as the rains start fuh rill, dog.
 
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Eastside

Life of the Party
Forum Supporter
I run my outboard most of the year, except when there is snow on the ground in the Tri Cities. Tilt the motor vertical after pulling it out of the river to drain the water. We also run non-ethanol in our boats (wife has a 19 ft Mastercraft ski boat). After winterizing, the Mastercraft battery is removed and put in the heated portion of the garage for the winter. I will also pull the battery for the outboard when it gets really cold. This year, I have a new boat with a 4-stroke and a live well. There are instructions for draining the live well and disconnecting the water supply. I’ll follow the directions for winterizing that. Outboards are great for running year-round!
 
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Squatchin

Life of the Party
Forum Supporter
Last winter I filled my tank on my little merc 3hp with non-ethanol gas and added stabilizer. I actually hadn't gotten around to using it all year this year but I am planning on taking it out this weekend for a final warmwater 'hoo-rah'. So in anticipation I set it up to for a test run while on the stand. Fired up on second pull. So I guess she's good to go. (Knock on wood) Only thing I do is use good gas and let the carbs run dry after each outing.
 

Hem

Life of the Party
I went through the ropes a few years back learning the basics with outboards.
One little trick that may, or may not, prevent an issue is to put a little tape over the ports that expel water through the cooling process. Bugs sometimes climb in there and die. Sucky if the outboard overheats from blockage.
 

Jeff Dodd

Steelhead
I picked up some good tips in your thread Josh. Thanks

I prefer Yamaha fuel stabilizer over “stabil”.

Yamaha also makes an anti-corrosion spray that I use liberally under the coweling.

Non-ethanol fuel all year round for me, and fuel preservatives all the time as well. With small outboards, normally no fuel/water separator between the tank and outboard, so the conditioner minimizes effects of condensation
 

SurfnFish

Life of the Party
Forum Supporter
advice from a factory ob mechanic when winterizing a four stroke = add stabilizer to fresh non ethano, run it up to temp, shut it down and leave it hanging vertical..done. Do not run dry as the fuel keeps the gaskets from drying out, and no need to fog.
 

kerrys

Ignored Member
I’m curious what others think. I have always thought that 2 cycles don’t need as much care as far as winterizing goes. I believe that the oil used with 2 cycles helps protect them by keeping the rubber parts, seals, gaskets, hoses, ect, from drying out. I usually run none ethanol fuel but I’m not religious about it because of my beliefs on 2 cycle engines and 2 cycle oil. What do you think?
 

steelheardr99

Steelhead
Forum Supporter
I’m curious what others think. I have always thought that 2 cycles don’t need as much care as far as winterizing goes. I believe that the oil used with 2 cycles helps protect them by keeping the rubber parts, seals, gaskets, hoses, ect, from drying out. I usually run none ethanol fuel but I’m not religious about it because of my beliefs on 2 cycle engines and 2 cycle oil. What do you think?
Thats what i do with my old 2 stroke Kerry just add stabil to the non ethanol fuel i run all the time and put it away. In the spring a new set of plugs, new fuel/water separator and grease all grease points and away it goes. Been doing this since i bought it 15 years ago.
 
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