Major two stroke screw up Force 120

[Ampman]

Hello everyone, I made a stupid, village idiot style mistake. I've had a free project Bayliner that hasn't run in years for a while, finally got it running. I have no real experience with two stroke anything, other than a scooter when I was a kid. Probably can see where this is going.

During fill up, I ran out of the oil they came with the boat and used a Lucas two stroke oil which turns out to not be rated for water cooled engines. About 50% of the oil is the correct stuff in a 25 gallon tank. I know this isn't good/ok to do now. I bought what was available to me not thinking about it, as this is my first time filling this thing I didn't think about it. Stupid.

Will it survive one tank like this? Can I run it down 1/3 tank and correct it slowly? Can I drain it half way and fill it up right to reduce the amount of my mistake that's mixed into the fuel? I do not have anywhere to put a full 25 gallons of fuel and finding spare cans this time of year in my area is damn near impossible. Thank you for any advice.

 

[Redbarron%%]

You should be OK. (I think).
The air cooled oil is made for higher temps than the water cooled engine (hopefully).
Also the outboard motor oil is also designed to eventually break down in the water to some extent.
There may be many who know more than I do on this subject.

 

[roscoe]

run it down 1/3 tank and correct it slowly
Risk is that the air-cooled oil will not completely burn off due to the lower operating temp of a water cooled outboard. So you may foul a plug, or cause a little carbon build up, but should not be a problem for this limited amount.

Maybe add a little more tcw3 to start.

Curious as to you location, that you can't find gas cans?
You could always get a few online, then you could drain half and put proper oil fuel mix in the tank.

I like these, have several for the atv, boat, snowblower, lawnmowers, chainsaw.

 

[las]

Like the others I don't think there's a problem besides maybe fouling the plugs. But I believe it's more of a oil to water thing and very little with engine operation.
But don't add extra oil because then you will foul the plugs and actually risk running lean. It seems counterintuitive! But remember the the carb doesn't know how much of the mixture it meters that are oil.

 

[jerryjerry05]

As long as there's oil you should be ok.
The TCW3 was designed to burn "clean" and regular oil and the older TCW2 and the oil originally used when burned it would leave a residue and eventually carbon would seize the rings and POW there goes another outboard.
Bought a new 88 with twin 85hp. Forces
Used good oil TCW2 and 4mo later went to start it and found I had low compression on 2 cylinders. The TCW2 was designed to leave carbon and had 'ash" in it and was to burn dirty and cause problems.
Since I worked at the dealer I re-ringed my own motor.
Then tested the second motor, same problem.
Then they introduced TCW3 and all my problems were solved.
Never had a problem with carbon again.
Just the amount you have mixed in wont hurt. Just don't do it on a regular basis.

 

[roscoe]

Like the others I don't think there's a problem besides maybe fouling the plugs. But I believe it's more of a oil to water thing and very little with engine operation.
But don't add extra oil because then you will foul the plugs and actually risk running lean. It seems counterintuitive! But remember the the carb doesn't know how much of the mixture it meters that are oil.

You're really gonna have to explain how a plug not firing will cause a lean condition.

Fuel and air will still be going thru the cylinder even if the plug doesn't fire.

 

[Lou C]

I’m not sure about this either but the theory I heard on power equipment discussion boards was that adding more oil to the same quantity of fuel makes less fuel available and in turn leans the mixture which makes it run hotter. I have five 2 stroke machines, one is 23 years old two are 15 years old the other 2 are about 10 years old. All run great and have been run on the best semi syn 2 stroke oil I could find, carefully measured.
Interestingly one is a Toro snow blower with a Suzuki 5hp 2 stroke. Toro always specified the water cooled oil for these machines (TCW3) so that’s what I used. I actually asked a Toro tech why this was so and they said the snow blower engines run at much lower rpms than saws and blowers and can get deposits when run on the air cooled two stroke oil. The rest get Echo semi syn for air cooled 2 strokes.

 

[roscoe]

Well that kind of flies in the face of the owners manual that tells you to use double oil 25:1 during the break in process.

 

[las]

Hey, like Lou said. More oil = less fuel and like I said, the carb can't tell what oil % you run. Sparks not firing has nothing to do with it.
I bet the manual also states not to go flat out the first few tanks.

 

[Nordin]

Like jerryjerry says, run it with the mixture you have.
TCW-3 is the next generation of TCW-2 and the 2T oil for water cooled engines are made for lower engine temperature then air cooled two strokers such as motorcycles, moped, chain saws etc.
Run with the mixture you have until it is time to refill and then change to TCW-3 oil and 50:1 ratio.