Fuel:Oil Ratios

[The Boat House]

Running less oil is more about concern for the water
were you run you motors and protecting the opportunity
to run them. It only takes a small government like a
home owners association to control your access to water.
There are already lakes out west that don’t allow two
cycle motors anymore. Putting a large oil slick on the
water or running a smoky motor can get the attention
of the wrong people. Manufactures were
recommending the reduction in the amount of oil to
run with the introduction of an oil made specially to be
mixed with gasoline. (TCW) It important to be
comfortable with the amount of oil your running because
your not going to have a fun day if you think you could be
hurting you motor. This is some of the factory oil
recommendations put out in the early 70’s. You may find
this helpful in deciding what is the right amount of oil for you.

[Mumbles]

I have the same list Tubs posted in my ’80 Parts Guide but I strongly disagree with a few things on it. First, I would never run an AD or pre ’61 CD motor on anything less than 16:1 because of their rod bearing design. The same goes with the three horse JW-JH series of motors although they will live on 24:1 mix. At least they got the TN right at 16:1 as it needs the extra oil to seal itself.

You might notice that lots of these 50:1 motors from the sixties and seventies have vanished but there’s still lots of motors in use from the fifties and forties. I wonder if it has something to do with the little bit of extra oil added to the mix?

[chris-p]

Agree with Mumbles. That list is crazy. Good way to destroy our hobby in my opinion. I personally would like to see my grandkids enjoying my motors, and their grandkids after them. I have a SHED full of Johnson CDs and ADs where the owners followed "Bob the Builders" advice down the street and ran them on 50:1 and they detonated. Spending an extra couple bucks on oil per tank is NOT going to destroy our Lakes and Water front. Being irresponsible will. Keep your motor in proper tune and enjoy them.

I take my kids around about once a month in the summer time to pick up trash from around our local lakes we enjoy. Teach our young ones to take care of our wildlife. We don’t need to destroy our hobby and the limited number of motors left running to do that however. Just my 2 centos.

[outbdnut2]

I believe that 20 to 1 instead of 24 to 1 and 40 to 1 instead of 50 to 1 give some cheap insurance, and I like that these ratios are easy to mix, being 1 quart to 5 gallons and 1 pint to 5 gallons, respectively. My 16 to 1 motors get 16 to 1, but if it’s a short run in a test tank, I sometimes use 20 to 1 for convenience because I usually have a can mixed. I buy generic TCW3 oil by the gallon at Walmart or Fleet Farm.
I do not skimp on oil. In my PO 22 HP Johnson, I run 8 to 1 as the decal says. It does not smoke after it gets up and runnin’.

Note that the Champion Hotrod racing motors called for a 4 to 1 mix! When do you start calling them a diesel?
Dave

[Mumbles]

quote outbdnut2:

When do you start calling them a diesel?

When they say AMARC on the hood! ☺

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Attachments:

[1957evinrude]

I would not risk using less than the recommended oil from the manufacturer. I believe too much oil is better than not enough.

[1946zephyr]

quote Mumbles:

I have he same list Tubs posted in my ’80 Parts Guide but I strongly disagree with a few things on it. First, I would never run an AD or pre ’61 CD motor on anything less than 16:1 because of their rod bearing design. The same goes with the three horse JW-JH series of motors although they will live on 24:1 mix. At least they got the TN right at 16:1 as it needs the extra oil to seal itself.

You might notice that lots of these 50:1 motors from the sixties and seventies have vanished but there’s still lots of motors in use from the fifties and forties. I wonder if it has something to do with the little bit of extra oil added to the mix?

I completely agree here. The little 3 horse needs the 16:1 because there isn’t any needles in it, except the later ones having the top crank bearing on needles.
Oil is the cheapest thing you’ll ever put in an outboard

[shane-r13]

I always thought it was low on compression. It was used many years pushing heavy loads up a river. I’ll have to look into that once i get all the other projects finished.

[jerry-ahrens]

I’ts surprising to me how many outboards come through my shop with either no thermostat, or a faulty one that’s stuck open. This seems to be an often overlooked area in the cooling system. As Mumbles pointed out, an engine will never come up to operating temperature and ”burn off” if running to cold. I see it on Mercruiser engines too…nobody bothers to check!

[garry-in-michigan]

It seems most casual owners think checking an outboards operating temperature is to look for smoke. You know them, they have there spotless owners manual tucked safely in the kitchen junk drawer . . . 😀

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