accidental mix of 15w40 four stroke oil instead of two stroke oil

[andros]

I accidentally put in my tank 15w40 four stroke oil instead of two stroke oil.
Can i top it up with more gas and two stroke oil or do i have to empty the tank?
It is a trophy with 80 gallons of gas.

 

[jonesg]

Re: accidental mix of 15w40 four stroke oil instead of two stroke oil

More info would help, I guess its an outboard.
How much oil did you add to how much fuel was already in the tank.

 

[andros]

Re: accidental mix of 15w40 four stroke oil instead of two stroke oil

the engine is an outboard 120 force.
There was already 1/4 tank petrol and i added 50 litres of petrol and one litre of 15w40.
I plan to add 50 more liters of petrol and one more liter of two stroke oil.
would this help?

 

[eurolarva]

Re: accidental mix of 15w40 four stroke oil instead of two stroke oil

My guess is that the original oil you mixed is not soluble in gas which means it will separate. If you add the gas you mentioned the 50 liters to 1 liter of oil you will then have a 100 to 1 mix. If you are not going to siphon off the old gas I would add another liter of oil to the first batch. If the original gas does mix with the oil the worst thing that would happen is that that gas would be 25 to 1 which is the ratio to break the motor in in the first place. I have no idea what effect that motor oil will have on your motor. I am guessing fouled plugs at least.

 

[45Auto]

Re: accidental mix of 15w40 four stroke oil instead of two stroke oil

Put an additional liter of 2-stroke oil in with the additional 50 liters of petrol. Ignore the 15w40 you accidentally added, you'll never notice it. It won't make any difference to your engine. Worst that'll happen if it dissolves completely is that your mixture will be around 33:1.

You won't see any effect on plugs, etc. You don't have enough 15w40 in there to make any difference.

 

[Vic.S]

Re: accidental mix of 15w40 four stroke oil instead of two stroke oil

I believe the multigrade will mix with the gasoline, it might not mix quite as quickly as 2T oil will but it will mix and it won't separate. Pity you can't pick the tank up and give it a bit of a shake.

Having added the 50 litres of gasoline to go with the 1 litre of oil I think you will be ok. Don't add any extra 2T oil though, enough oil is enough oil.

You could add another 50 litres of gasoline + another litre of 2T oil to dilute the multigrade as you suggest. Good idea probably.

The engine might smoke a bit as the multigrade may not burn so completely. An extra 50 litres of 50:1 mix will help but it will be longer before you get back to normal.

 

[Frank Acampora]

Re: accidental mix of 15w40 four stroke oil instead of two stroke oil

A WORD TO THE WISE!---Multi-Grade Automobile oils contain additives that are harmful to two stroke engines.

Based upon my experience -- I ruined a piston almost immediately upon switching to a six gallon tank with one pint of 10-30 auto oil -- I would drain the tank and refill with proper mixture of TCW-3 oil.

It may not affect your engine as badly, but why take a chance? The gas, while expensive, will be cheaper to discard or use in your lawn tractor, than the damage and repair it may cause.

 

[Lone Duck]

Re: accidental mix of 15w40 four stroke oil instead of two stroke oil

A WORD TO THE WISE!---Multi-Grade Automobile oils contain additives that are harmful to two stroke engines.

Based upon my experience -- I ruined a piston almost immediately upon switching to a six gallon tank with one pint of 10-30 auto oil -- I would drain the tank and refill with proper mixture of TCW-3 oil.

It may not affect your engine as badly, but why take a chance? The gas, while expensive, will be cheaper to discard or use in your lawn tractor, than the damage and repair it may cause.

Yep!