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Sorry another oil Thread ?

David Martin

Jet Boat Junkie
Messages
635
Reaction score
462
Points
147
Location
Punta Gorda
Boat Make
Yamaha
Year
2013
Boat Model
SX
Boat Length
24
Hey guys have a question Yamaha manual gives the oil type as SAE 10w30, 10w40 20w40 20w50 as approved by their engineers for use in the 1.8 l engine........... API quality SJ SN or above.

Hears my question ? has anyone out hear in a Jet Ski or Jet boat used 10w30........it is approved by Yamaha. !!!!!!OK OK I'm retired and bored out of my mind.........LOL Just Asking.
 
well, i haven't.
the 10w30 is their 'cooler' temp area suggestion...and it gets hot as ass here in tx...so i went a bit higher up the chart, use 15w40 rotella t4...
my diesel pickup wants 5w40 for cold areas and 10w30 for warmer climates
 
I use 15w-40 in mine. 10w-30 would be better in a cooler setting but when its 100+ in the summer, it'll be more like water, resulting in less lubrication and more engine heat and most likely a reduction in engine performance if these engines retard timing.
 
Same as others here. My average boating day is probably 110 so I would never use 10w30 here.

If I lived far enough north I sure would to avoid wear on the engine while the oil warmed up.
 
Don't see much reason to use anything but 10w-40. Just ordered oil yesterday so I was looking this up. ***edit, unless you boat in AZ***. :cool:
1714049825721.png
 
does anyone use 20w50?
 
I use 10-40 but maybe I should be using 20-50 in summer based on that chart.
We don’t get enough hours to change oil more than annually though.
 
I use 15W40 T5 simi synthetic right now. I think due to the hot temps hear in Fl I'll just stick with 15w40 but just had to ask. I don't think it would harm the motor but 30 weight have a slightly lower sheer than the 40 would have to be changed more often. I have had a lot of experience in big V8 in boats like merc.......volvo ect and 30 weight is used regularly but, none of the 350 or 496 big iron turn 7250rpm like my 1.8L..... Looks like a 10w30 would have to be changed less hours.

I just got my oil test results back from BlackStone Labs and my motors are extremely low on wear metals the only metal that was in the middle of normal is iron/cyl wall everything was else almost Nill 1 or 2 parts per million when averages for these motors were are in the 20 parts per million for mains, cam lobes ect............BlackStone recommended I extend to 75 hours per change as the T5 shows a lot of protection and additive left.

I talked to them on the phone about wear and why Conventional, Simi Synthetic and even doubling the Moly had almost no effect on wear I swear I heard my Dad..........Motor oil is motor oil........I believe that's been said out hear more than once also. It looks like most of the difference in oil is the color(flavor)of the bottle and the price per quart as long as you meet the SAE and API the mfg tells you to use. Thay all will protect the Yamaha engine.

Thanks guys and boating weather is getting better for most of the country..........Sorry but not sorry Florida is all year long.
 
I'll be boating in AZ and NV where it easily reaches 100-115. I want to use 20W40 or even 20W50 according to the chart but it's difficult to find... and why do they only have a picture of an outboard on their packaging? 😁
 
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I'll be boating in AZ and NV where it easily reaches 100-115. I want to use 20W40 or even 20W50 according to the chart but it's difficult to find... and why do they only have a picture of an outboard on their packaging? 😁
Thing to keep in mind is that this isn’t a car, your boat has an unlimited supply of lake water that is 80-85°?, to cool the engine with, whereas a car only has the 100-115° air to cool the engine with, and your boat has a separate oil cooler.

Since you bought this boat in CA I’m assuming it’s a four start model, the API oil designation should be SJ or higher.

IMG_0230.jpeg

Looks like you can find the 4T 20W-50 power sports oil most places, and it’s API SJ but it’s not FC-W rated.


As you probably found you can find the Yamalube 20W-40 oil which is FC-W (four cycle watercraft) rated.


The 68° Winters number of the 20W-40/50 oil seems a bit high to me but as long as you’re not running the engines at 68° or cooler it would be fine. It doesn’t look like Yamalube marine is available in 20W-50 ask your dealer parts dept.

I run 10W-40 Amsoil marine oil, I wouldn’t have any reservations about running this oil at Lake Powell in the summer where lake water temperatures are 85° and air temperature is 115° or higher.

Don’t be put off by the pics of the outboards…the 10W-30/40 oil has the same pics.
 
You are very correct and I thought about your point that it'll have unlimited supply of cold lake water and it shouldn't matter the air temp but I also thought then why do they list the higher viscosity oils.
 
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