What octane gas to run? Ethanol free required?

Glastron Boater

Petty Officer 3rd Class
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Jan 22, 2017
Messages
97
I read the post in the FAQ section, but I would just like to verify here I understood.

The FAQ section said use a good quality mid-grade gas, so in my area this is 89 octane.

It also said to mix 50:1 with TWC3 2 cycle oil.

Can someone translate that for a dummy?

I have other 2 stoke tools and I mix the oil, but I'm not used to the huge tank on this, and I can't recall the oil mix on the tools off the top of my head...


How do you recommend mixing? Pre-mix in 5 gallon tanks or just fill up the boat?

I just don't want to burn up this outboard.


Thanks in advance.
 

wrvond

Chief Petty Officer
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Mar 2, 2010
Messages
597
It means you use 50 times more gas than oil in your mixture. All my two stroke yard tools use 50:1.
1 gallon of gas needs 2.6 ounces of oil
2.5 gallons of gas needs 6.4 ounces of oil
5 gallons uses 12.8 ounces of oil

If your gas tank is empty, simply add the appropriate amount of oil then fill with gas. Otherwise, you can fill the tank, make note of how much gas you put in, then add the appropriate amount of oil.

If you are used to mixing oil and gas in 5 gallon cans, then go with what you know, You are less likely to make a mistake that way.
 

pnwboat

Rear Admiral
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Oct 8, 2007
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4,251
This is what I use to mix. All of the Force outboards run 50:1 like wrvond says. Look at the mixture ratio at the top (there are several different ratios 33:1, 40:1, 50:1 etc), fill up your tank and make a note of how many gallons you put in. Look at the gallon/litre scale under the 50:1 ratio and fill the bottle with oil to that line and pour into the tank. Very simple.

Note: Ethanol free gas is most desirable, however, hard to find these days. I've been using 10% ethanol for years and it's worked for me. These motors older design and not high compression motors so high octane fuel has no performance advantages. FuelMixBottle.jpg
 
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GA_Boater

Honorary Moderator Emeritus
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On the way to the lake or on the way back home I fill the tank to even or 1/2 gallons. For example, 10 gallons or 10 1/2 gallons. I use a measuring bottle just like one the one pnwboat showed above. Simple. Driving to the lake does all the mixing needed. TCW 3 is the only type of water cooled outboard oil you can buy.

As far as gas goes, put gas in it. From the Force 85/125 Owner's Manual here - http://www.reinsmith.net/gallery/boa...ers_Manual.pdf

It says to use 87 octane. You can use E0 if you can afford it and don't use you boat much.;
forceoct.PNG


Followed by, ignore the US marine oil part - It can't be found anymore, use TCW 3;
forceratio.PNG
 

SkiDad

Lieutenant Commander
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Jul 18, 2010
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I usually just dump in 1 quart of oil and then add 12.5 gallons of gas. It mixes fine that way. I always run 87.
 

Glastron Boater

Petty Officer 3rd Class
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Jan 22, 2017
Messages
97
Ok seems simple enough.

And I can get Ethanol free at a local WaWa gas station. But if it's not required on these 2 stroke engines then I won't go out of my way. I do plan to use the boat a lot, every weekend or every other weekend.

My gauge currently reads 1/2 tank, and that's what was in it when I got the boat about 1 month ago. I don't know how old that gas is, but seller claimed to have used it last year...


Can I use SeaFoam (fuel system cleaner)?

Boat seems to run fine (only had the opportunity to run it for a short period of time at a time)


Where can I buy those measuring bottles?
 

jerryjerry05

Supreme Mariner
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May 7, 2008
Messages
17,923
NEVER put the gas in first.
You can add the oil after the gas is in and the oil can settle on the bottom of the tank and not mix well.

​I can see my tank and the amount of gas needed.
But I still add 1 pint or 1 quart. then add the fuel.
​Then another pint or quart and then fuel.
​That way it makes sure they mix.

The TWC-3 is: two cycle water cooled.
​The #3 is the end of a series of crappy oils produced over years of PAIN!!!

​The first outboard oil was designed to have excessive ash amounts
and that made the rings carbon up and seize and cause the motor to loose compression.
​#2 was a but better but still was causing the problem.
​#3 finally was the right combo and stopped the carbon problem.

Bought a new boat in 88 twin 85hp Forces.
​The old oil carboned up BOTH and I had to re-ring them with-in 1 year.
I did a lot of slow trolling which contributed to the failure.
​Luckily I was able to fix it before there was any bad damage and just replaced the rings.

​If you don't have a good fuel gauge??
I'd add 1 pint then 6 gal. Then repeat.
​That way if you add too much oil it won't over oil.

​Too much oil isn't as bad as no oil but too much can hurt.
​They can still cause carboned up rings.
 

ondarvr

Supreme Mariner
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Apr 6, 2005
Messages
11,527
First, don't stress over any of it, if you don't get the oil ratio exact it will be fine, also the motor will run on just about any gas except E-85. If the boat's on a trailer it makes no difference when or how the oil is added to the tank, two blocks from the gas station and it will be mixed well.

Gas gauges are rarely accurate, so don't depend on it for anything.

​The mix bottles are sold at Walmart and many auto parts stores for a couple bucks.

​Just do the best you can and it will all turn out fine.

​The old oils don't contain ash, the ash deposits are from normal 2 stroke oil being used in water cooled outboards, those oils leave ash deposits at the lower temperatures and lower RPMs where outboards operate. The TCW oil formulas have changed over the years to improve their performance. Don't use outboard oil in other air cooled 2 strokes, and don't use air cooled 2 stroke oil in an outboard.
 

Glastron Boater

Petty Officer 3rd Class
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Jan 22, 2017
Messages
97
OK thanks, I'll make sure it's the marine 2 stroke oil. I haven't been back to the store to pick some up, but I didn't know they were different for water cooled or air cooled. I was just going to look for that TWC 3.
And I won't use the synthetic oil I use in my 4 wheeler, as that is air cooled.

The boat is trailered, and I was thinking the oil and gas would be mixing as it is being driven to the ramp, as well as when driving through the water going over waves and steering etc.


I'm planning to pull the gauge unit out and see if it actually has 1/2 tank. I don't want to run out while on the water. I am definitely bringing extra gas and oil with anyways, but I don't want to go out with 1/4 tank when I think it's 1/2.


I won't stress too much about the octane rating. I usually run 87 in yard tools and my 4 wheeler, and didn't have too many problems. Only problems came from when they sit too long.
 

CJ River Rider

Petty Officer 3rd Class
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Sep 4, 2012
Messages
90
Don't use outboard oil in other air cooled 2 strokes, and don't use air cooled 2 stroke oil in an outboard.

Why is outboard oil NG in 2 stroke air cooled motors? I always have gas left over at the end of the season & save it for an old Snapper snow thrower. The only thing I do besides treat it is add a little more oil to get to a 32:1 ratio.

BTW, I use the Pennzoil XLF brand.
 

ondarvr

Supreme Mariner
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Apr 6, 2005
Messages
11,527
Air cooled 2 strokes typically operate at higher temperatures and higher RPM's, outboard oil doesn't do well in that application, bearing failure and scuffing can be a result..
 

jerryjerry05

Supreme Mariner
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May 7, 2008
Messages
17,923
CJ. The Clymer manuals aren't really engine specific.
​They cover a BUNCH of models and really don't cover an individual motor.
Try e-bay for a manual specific to your motor.
​Or get one from Mercury, a lot more expensive but much better.

​I lived in Md. and the local library had factory manuals.
​Maybe find the book code and ask your local librarian if they can get it??
 

Glastron Boater

Petty Officer 3rd Class
Joined
Jan 22, 2017
Messages
97
CJ. The Clymer manuals aren't really engine specific.
​They cover a BUNCH of models and really don't cover an individual motor.
Try e-bay for a manual specific to your motor.
​Or get one from Mercury, a lot more expensive but much better.

​I lived in Md. and the local library had factory manuals.
​Maybe find the book code and ask your local librarian if they can get it??

That's a good idea. I have the Seloc book now, but I should have checked the library. They do have a lot of the car manual, the Haynes ones, which are similar.
 
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