20:1 or 24:1 in '56 3hp ?

[kyron4]

Hello, I have a 1956 Evinrude Lightwin 3 hp. I've had it about a year and it runs great. I've been running 20:1 mix in it and it runs fine without smoking. A mech. buddy told me I only needed to run 24:1. Is there any negitive effects from running a higer oil mix ? My thinking was a little extra oil would help those bronze bushings last a little longer. I'm running 87 oct. and Mercurey TC-W3 outboard oil. Any advice or opinions ? -Thanks

 

[tashasdaddy]

Re: 20:1 or 24:1 in '56 3hp ?

16:1

 

[JB]

Re: 20:1 or 24:1 in '56 3hp ?

"Official" publications can be found that recommend 16, 20 or 24:1. BRP most recently (to my knowledge) specifies 16:1, but don't get your knickers in a twist about it.

My Johnny JW-13 was almost exactly the same engine and used 24:1 for about 10 years with no problems. There are thousands of pre-1970 JohnnyRudes out there doing the same thing and earning the devotion of their owners.

The truth is that engine can live a long and fruitful life on a wide range of mixes using TC-W3.

If I had my li'l Johnny back I would still run her on 24:1.

 

[F_R]

Re: 20:1 or 24:1 in '56 3hp ?

It probably was marked 1/2 pint per gallon (16:1) when new. However, the people that made it revised that to 1/3 pint (24:1) in December 1960. Note that was before the 50:1 oil was introduced. 16:1 as originally spec'd certainly won't hurt it and the tiny bit of extra oil in that gas-sipper won't break the bank. This question always starts a fight, and I am only presenting what Evinrude Motors said in 1960. BTW, some of the BRP engineers probably weren't even born yet in 1960. I really don't care what anybody wants to use, but personally I use 24:1 in my '56 Lightwin.

 

[steelespike]

Re: 20:1 or 24:1 in '56 3hp ?

Just for further info my 55-67 aftermarket manual lists before 59 16:1 59-63 24:1
after 63 50:1 I believe the 50:1 motors may have redesigned bearings but clearances are the same for all years.No ball or roller bearings until 68.

 

[kyron4]

Re: 20:1 or 24:1 in '56 3hp ?

Thanks for the input guys. To be clear it would have no negitive effects or effect preformance to run as high as 16:1 or as low as 24:1 ? I only go through about 5 or 6 gallons a year so if 16:1 is whats needed its not any big deal. Another question, since I'm new to 2 cycles, is will the "thicker" 16:1 mix cause the motor to run slower or less smooth, or foul the plugs and cause carbon build up ? -Thanks

 

[rjezuit]

Re: 20:1 or 24:1 in '56 3hp ?

If you use that little, try the synthetic or semi-synthetic blend. They are cleaner, and better for the environment, smoke less and build up less. All of the new oils produce much less ash and deposits that years ago, but yes, they will foul plugs more at a higher ratio. Rick

 

[kbait]

Re: 20:1 or 24:1 in '56 3hp ?

24:1 regular outboard oil mix w/non oxygenated fuel (if available). Carry an extra set of plugs, a screwdriver, and you'll get across Superior!

 

[1946Zephyr]

Re: 20:1 or 24:1 in '56 3hp ?

At WOT, they'll be less likely to foul, than if you're doing a lot of trolling.

 

[kyron4]

Re: 20:1 or 24:1 in '56 3hp ?

At WOT, they'll be less likely to foul, than if you're doing a lot of trolling.

I'm sorry , what's "WOT" ? wide open throttle ?
-Thanks

 

[tashasdaddy]

Re: 20:1 or 24:1 in '56 3hp ?

yep!!!

 

[Vic.S]

Re: 20:1 or 24:1 in '56 3hp ?

Another question, since I'm new to 2 cycles, is will the "thicker" 16:1 mix cause the motor to run slower or less smooth

you may find at these high oil levels changing the ratio by very much will affect the mixture adjustment.

I run a couple of British Seagull engines. Originally they used a 10:1 fuel: oil mix but I have converted mine to use (like later versions) a 25:1 mix. Doing that has required a change in the metering needle in the carbs. (other models with a different type of carb require different jets)

I'm not sure whether it is the "thickness" or viscosity of the mixture that affects them or if it is just that if there is more oil there is less gasoline in the mixture.

BTW the official recommendation is that most motors from 1958 and prior will run on 20:1 see http://www.evinrude.com/en-US/About.Us/FAQ/Oil.Fuel.htm However if TD is recommending 16:1 he probably has good reasons to do so.

 

[MudLake]

Re: 20:1 or 24:1 in '56 3hp ?

I have 1955 Johnson 3 hp weedless and I running yamaha 100 to 1 mix but mix it at 32 to 1. Been doing this for 20 years and it still runs great.

 

[JB]

Re: 20:1 or 24:1 in '56 3hp ?

NO official publication that I am aware of suggests using Yamaha "100:1" oil in a 55 Johnny 3HP, OR of mixing 32:1 for that engine.

As I said, that engine will tolerate a wide range of fuel mixes. I should have added: .. .including some that are risky stunts.

 

[wbeaton]

Re: 20:1 or 24:1 in '56 3hp ?

NO official publication that I am aware of suggests using Yamaha "100:1" oil in a 55 Johnny 3HP, OR of mixing 32:1 for that engine.

As I said, that engine will tolerate a wide range of fuel mixes. I should have added: .. .including some that are risky stunts.

I'm not going to say that 32:1 is a risky stunt. I'm also not going to say the OMC recommendation of 50:1 stamped on the front of my 1967 Johnson 3 hp is a risky stunt either even though the motor is the same inside as the first 3 hp built in 1952. Fact of the matter is that these engines will run on whatever you throw at them 16:1, 20:1, 24:1, 32:1, 50:1. Use what you want. Personally, I err on the side of caution and use 24:1 with synthetic outboard oil in both my 1952 and 1967 Johnny 3 hp's. OMC and BRP have both revised the recommendation so many times its ridicules. Since the motors internally were unchanged from 1952-67 the arbitrary cut offs of say 16:1 prior to 1958 and 24:1 from 1958-1963 doesn't apply.

 

[muskrat]

Re: 20:1 or 24:1 in '56 3hp ?

If you use that little, try the synthetic or semi-synthetic blend. They are cleaner, and better for the environment, smoke less and build up less. All of the new oils produce much less ash and deposits that years ago, but yes, they will foul plugs more at a higher ratio. Rick

I have been running full syn oil in my 30 hp 1986,but it has not fouled a plug.What mixtures will foul & why???????

 

[tmcalavy]

Re: 20:1 or 24:1 in '56 3hp ?

The mixture itself won't foul a motor...more oil promotes plug fouling a low, sustained trolling speeds because the engine is not running at top efficiency...the higher end of the throttle range. Of course, if you take care of your plugs, know your motor and boat wisely according to water conditions, this will never be an issue, right?

 

[OldJohnson6hp]

Re: 20:1 or 24:1 in '56 3hp ?

pre 60's running 20-1 seems right..Motor runs cool and DOES NOT foul plugs..I'll take 'em out and they're golden brown. Yes at low/idle speed it'll smoke a bunch but a good WOT run and its cleaned up.