Year-round oil weight for Mercury 50hp fourstroke???

jimmbo

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Use whatever you want. You keep asking questions looking for someone to agree with what you have decided
 

racerone

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There is so little understanding of what oil is and how it " works " in bearings.-----The conversation is endless !!
 

GA_Boater

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Suzuki specs 10w40...why wouldn't 10w40 be a good year-round oil in an outboard?

Get a flashlight and go look at the cowling on the motor. Does it say Suzuki? :doh:

Use what you want because you're ignoring everyone, including Mercury. Why did you ask and start this thread?
 

USA_boater

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well I have plenty of time to mull it over...17 more hrs of run time if I listen to the dealer who told me Merc took the 20hr first oil change out of the manual a few years back but it really still should be done; OR 97 more hours if I listen to the manual. So why not feel satisfied when I finally reach which ever point I do the first oil change?

As part of this mulling, I learned that the Merc 10w30 is API SJ rated and therefore is probably one stout oil for a flat tappet cam motor. Most of the the others (Lucas, Sierra, West Marine, etc.) are SL at best or even SM rated so they can be catalyst compatible. So score one for the Merc/QS 10w30...starting to look better. I'm a big fan of being able to get oil change stuff at wally world though, and they sell both grades of the QS just dino-only version, and the proper oil filter for this outboard. No more hours than I'll be putting on the motor, I bet the 10w30 wouldn't shear too bad before it got the end of season oil change. But generally speaking, I felt a 10w40 fit the temp range I was going for better. I deserved the hazing...I know.
 

jimmbo

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This looks like it it might make you happy, it's not FCW certified, but
Wally World has it, and it has thinness and thickness. Personally I wouldn't use it, but...
IMG_1538a.jpg
 

MTboatguy

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I use Rotella in my diesel pickups for year around use, but I would not use in my boats.
 

USA_boater

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Well I use Rotella in my inboard because it is convenient to use the same thing in the generator and the tractor and the boat; but I'll probably switch now that I am aware of the FC-W spec. As far as the 0w40 goes, I'm not in Alaska. I was just wishing that Merc allowed for 10w40. Interestingly enough, their SJ-rated oil says catalyst compatible. I thought all the older API ratings had too much Zinc & Phosphorus for cats. I don't have one so I won't obsess over it like i have the oil weight LOL.
 

USA_boater

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As I am a fan of being able to get stuff locally when I need it, I found that one of the local big box stores actually carries the Quicksilver 25w40 SYNTHETIC blend. I'd found the conventional 10w30 and 2w40 so I'd decided on the 10w30 until I came across this luck. I am expecting that I won't spend too much time in real cold weather and that the synthetic base will make up for the thicker oil for startup protection. This little Merc will be run wide open from spot to spot once it is fully broken in so I will feel better having the thicker oil for the RPM's. Just wanted to give an update on what I found and decided.
 

jimmbo

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Today I went into the Dealership. Lo and Behold, sitting on the shelf, was the Mercury Synthetic Blend 10W-30. About 25 cases of it. Arrived yesterday
 

USA_boater

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Today I went into the Dealership. Lo and Behold, sitting on the shelf, was the Mercury Synthetic Blend 10W-30. About 25 cases of it. Arrived yesterday

Well then that means what my dealer told me was true...As it gets colder now, I am quickly realizing I may not be out much when it is real cold. I have a whole winter's worth of work to do on my vehicles and house, AND I will be using the factory filled oil until next season anyway. Nobody could tell me for sure what oil would have come in my boat from the factory. As described above, I was told the dealer filled it with 10w30, I was told it shipped with 10w30, and I was told that all the Mercs sent to this region on the country come filled with 25w40. So I have no idea wha't in it now, but I have about 17 more hours to go before I need to do a break-in oil changed, or 97 more if I trust the manual.

Thanks for caring enough to report back to this particular thread jimmbo.
 
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