Starting A Four-Stroke With Old Fuel

[TMF89]

Hey guys. So unfortunately we didn't get around to winterizing our boat last year. It's got a F115 4-stroke Yamaha on it. If I remember right it's really low on gas, less than an eighth of a tank. I plan on putting about a third of a tank of gas into it and running it long enough to run out the old gas as soon as I get the chance. It's in our garage right now, which has a spigot for a garden hose that I believe wasn't drained for winter, so I should be able to use that to start the boat up. However getting the boat in/out of the garage is a real pain. At the same time though, I'd rather find out there's a problem at home in the cities than find out a few weeks from now when we're up in Baudette fishing the Rainy River. I was hoping I could (try and) start it at home with the old gas just to make sure it does (start), then add the new gas on the way up north (I go to school in Bemidji and I'm currently on break), and then when we finally take it out on the water let it run all the old gas out of the motor.

Basically I know nothing about small engines, so I just want to make sure starting it for a short period (just long enough to make sure it's running smooth) with the old gas won't cause any problems (at least any that would be remedied by adding the new gas). On a side note, are there any additives I should add either before i start it in my garage, or before we run it for the first time on the water? I know there are a ton out there, but nearly all mechanics I've talked to said they're mostly useless, so I figured I'd ask for some experiences on here. Thanks for the help guys!

[hydro]

No problems that I see with what you describe. Just put the cuffs on, feed it water and start it up. If anything, you may want to get some fresh gas and put it into the tank to dilute the old stuff. I would check the lower unit oil before doing anything, just for peace of mind.

[BoxMN]

I wouldn't worry about running the old gas out, just add new gas before you even start it (I use non-oxy in my small engines, woth the extra cents) and drive it like normal. I would run the motor as you plan just to give it quick test, but with good gas (even mixed with old) if it was running last fall, it should be running now Good luck, and good luck up nort'!

[reinhard1]

i run pure premium non oxy also in my 115 merc 4 stroke. i do winterize it but if you happen to skip one year and top it off it should not be a problem. i'm no expert on this but i have not had a problem since i bought the boat/motor in 2002. good luck.

[thatoneguy]

+1 on checking the lower unit fluid first, if you didn't change that out in the fall.

[TMF89]

Is lower unit oil the same as the regular oil or the gear lube, or something else? If so how do I check it? My mechanical skills are about nill lol.

I could probably add a little gas to it before starting it up at home, but it would probably be a pain since all our gas cans currently have mixed gas for two cycle motors in them. How fast would the motor run through the gas currently residing in it, and start eating up gas from the tank? Five seconds? Ten? Thirty? Thanks for the help guys.

[hydro]

The "lower unit oil" is gear lube. To check it, pull the bottom plug on the gearcase and let some drain out. Look for any sign of water or a milky brown color. The oil should be a dark brown but somewhat clear fluid.

If you do not add gas to the tank, you will not really accomplish much by running the motor other that reassuring yourself that it runs. To run out the gas that is in the carbs/injectors and the lines will take a few minutes. Just start it up and let it idle until it warms up and then turn it off. That's all you really need to do.

[SkunkedAgain]

For even more peace of mind, after running on the muffs at home, you can stick it in one of the rivers and test by going up stream. If it dies you can just float back to your truck. You should be fine, but it never hurts to take a paddle and/or make sure that your trolling motor is charged up!

[TMF89]

Sounds good, I can check that. And that's really all I'm after (assuring myself it runs) just because we can get it to a shop down here and probably get whatever it is fixed or tuned or whatever that day, and it'll be cheaper than having it done up there, and also be out a weekend of fishing. As soon as I see its running smoothly I'll turn it off, and the next time it'll get turned on it'll have 12 gallons of brand new gas to run through it lol. So that would be an alright plan then?

[hydro]

That is a great plan. Let'r rip!

[Kyhl]

If nothing was done before storage, I would plan on changing the engine oil and filter too.

Change the oil and filter,

check the lower unit lube,

add some fresh gas,

check the water fuel separator (if yamaha has a visual one),

put the muffs on,

run it (I expect it will run fine),

check the water fuel separator again when done to see if moisture was coming through from the tank.

[harvey lee]

I would use marine grade gear oil if your going to change the lower unit gear lube. Just a FYI if you did not know.

[TMF89]

Harvey thanks for the tip, I'm aware there's a separate gear lube for marine use. And could I just check the main engine oil to make sure it's still usable instead of just changing it? Believe me I'd rather change everything out and get it in tip top shape, but unfortunately I have the "college kid" budget, and my dad probably won't want to throw down money for the oil change.

[TMF89]

Well I talked to my dad and he actually seems to be okay with changing the gear lube and the motor oil. Any advice on brands/models to use? It's a 4-stroke 115 Yamaha.

[MN Shutterbug]

The question I have is, how the heck could you afford a motor like that in the first place, on a "college kid" budget"?

[TMF89]

Lol I guess I should clarify. "Technically" the boat/motor is my dad's (it's an 01 Lund Fisherman 1700), but the only time he even sets foot in it is if I get him to go out fishing, and since I have the family truck, he really can't use it anyway lol. It's to the point where after I finish school he's officially selling it to me for like $100 or something. lol

[MN Shutterbug]

I'll give him $200 right now.

[Can'tFishEnuf]

After you get the new fuel, throw some Seafoam in the gas to help clean out the carbs/injectors.

[TMF89]

Shutterbug, I think I'm going to have to decline on telling him the offer lol.

So I just started her up, and she ran for about 20 seconds. There was a SLIGHT climb in revs a couple times, probably three times it would rev up slightly for a couple seconds. Also I smelled a slight burning odor after. Never smelled burnt gas/oil before, but that's the impression I got. No smoke or anything though. What do you guys think? I did have the plastic cover off so everything was a bit louder than normal. Thanks!

[goose89]

Put the cowl back on. Get the oil and lower unit lube professionally changed. Fill the gas tank with gas and add 1oz. Yamaha Ring Free / 10 gallons of gas. Add these charges to the $100 purchase price of the boat when your dad sells it to you and forget about it.

[boatfixer]

How much seafoam did you put in? That has a distinct smell.

[TMF89]

Well I'm comfortable changing the oil/lube myself, I've watched a bunch of videos on the subject with the exact same motor. And what is Yamaha Ring Free? Just wondering in case I can't find it and have to buy a different brand. So what would causing the revving/smell?

[Matt C]

That 4 stroke yami is just like a car engine. Add some fresh gas, to that seafoam, your good to go.

That smell is the seafoam. No worries.

Change the oil, and the lower unit, and get fishin!

[TMF89]

Well guys I decided to check the gear lube to see what condition it was in. I unscrewed the bottom screw because everything I've heard said it would slowly drip out because of the vacuum. Well it decided to not do that, and a bunch came out and all over my hands and garage floor. I wiped my hands off and washed them, and took a pic of the fluid on the floor to see what you guys think. 1. Is that color indicative of lube that needs changing? I've heard change it if it's whitish or mustard colored. It's slightly lighter than the picture shows. 2. Is that much coming out going to require me to add more/change it anyway? Thanks guys.

Also I'm buying oil for the motor later today, what brand/model would you guys recommend?

[TMF89]

Sorry about the double post, but what about Quicksilver oil? They have some at the local GM. Anyone have experience with that? Thanks guys!