oil mix ratio

[joho5]

If my engine calls for 50:1, will it hurt the engine to run it at 40:1 and / or will it make it run different?

I have heard of folks doing this to be safe and make sure to always have adequate lubrication.

I have a 71 model outboard is why I am asking...its getting up there in age.

thanks

 

[Rick.]

Re: oil mix ratio

I can't think of any reason to go 40:1 just because of its age. 50:1 is the mix it is designed for and that will be sufficient to keep it in good shape. Better to use a good grade oil and fresh gas and seafoam additive. I have a 71 and the compression is right up and has always had a 50:1 mix. I read an article where a fellow uses 100:1 mix for trolling and then switches to a 50:1 tank for the trip home. Having said all that I doubt 40:1 will hurt anything but you might have to decarb more often. Your plugs will not likely foul at 40:1 . I have used 32:1 for a leaf blower that calls for 50:1 because all my other two stroke yard motors call for 32:1 and I can't be bothered to have an other gas can just for the leaf blower. I've noticed no performance issues with the leaf blower. Rick.

 

[tashasdaddy]

Re: oil mix ratio

run 50:1 as recommended, increasing out, will only cause more smoke, carbon build up. you might do a decarb on it. to clean the curd out of it.

 

[joho5]

Re: oil mix ratio

alright, cool.

I will just keep it at 50:1

thanks

 

[SoFloStone]

Re: oil mix ratio

Also, running an engine at 40:1 instead of 50:1 leans out the engine, and you should re-adjust your carbs...

 

[mthieme]

Re: oil mix ratio

I agree - stick to 50:1.
I add one extra ounce for a six gallon mix. No ill effects.