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yamaha mariner 40 hp, oil gas mixture

R

rglouc

New member
I've got a yamaha mariner 40 hp. It is 1982. I'm posting here as it's a yamaha flavored mariner.

I do not have the owner's manual.

What I need to know is how to mix the gas. Some places (on the internet) say 100:1, and some say 50:1.
 
100:1 is marginal lubrication.-------------------If you want the motor to last a long time I would recommend 50:1------------Others will tell you different.-----------------Motors will run on 100:1 at a higher rate of wear of the parts.
 
I understand. That's very helpful. I guess I've always thought of it like "use too rich or lean a mixture -> quickly mess up the engine." Damage over time from too lean a mixture makes a whole lot more sense.

But it makes me wonder why a person would go with less oil? Environmental reasons?
 
Most folks just do not know how lubrication is accomplished in a 2 stroke engine !!----Even seasoned mechanics are confused and have a misunderstanding of what happens.----------The oil must seperate from the fuel and coat the parts internally in order to lubricate and prevent wear.------------------Too little oil means that parts will wear at a faster rate !-----------Too much oil will never do mechanical damage !!!
 
NO NOT AT ALL--------------------When fuel and oil enter the airstream and go into the crankcase, the fuel evaporates and the oil seperates and is left behind in the crankcase to condense on all the surfaces like a microscopic rain.---------The fuel and some oil then is tranferred into the cylinder where combustion occurs.-------------As i said most folks are confused and think lubrication is an " instant thing "-----------when in fact it is not.----------Some of the oil that is lubricating the parts may have entered the motor say 30 seconds earlier !!
 
Racerone,
How does 4stroke lubricate their cylinder rings without burning all the crankcase oil :}~
 
The oil is totally seperate from the combustion chamber.-------------------Oil film on the cylinder wall is controlled by the oil scraper ring !!!
 
Very knowledgeable Racerone. Boaters on this site are blessed to have your support. Seems like you cover not only one mfg but many of them. You and master Joereeves help make this world a much better place to live.
Thanks
 
On ------U-tube ----------you can probably search for anything you want to know about outboards ------------Many " how to " videos on them as well.-------Some better than others.
 
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