2 stroke oil mix

The ancient Sachs Dolmar chainsaw I have just refurbished (it has a cam, points and a condenser!) has 25:1 stamped on the fuel tank cap. It should last forever although it kills the trees before I have a chance to cut them down. :(

Richard
Back in the 1970s my first Seagull, a 1948 102+, specified 10:1 but it was easier to run on 8:1 - a pint of oil to a gallon of petrol with no fussy measuring. Could get both for under 50p... :cool:
 
Hi can anybody help...how much 2 stroke oil at 50/1 how many ml to a 30 lt tank..many thanks

Strictly speaking, if you want a total of 30 litres once mixed, you would need about:

30 * 1/51 = 0.588 litres of oil

and

30* 50/51 = 29.412 litres of petrol.

Yeah, yeah, I agree, it will make booger all difference here, but sometimes in life correct calculations are critical
 
It's the Americans who always make me chuckle

They still work in ozs and gallons so working out how many ounces of oil to add to a gallon of "gas" is real feat of arithmetic gymnastics .

( 2.56 if anyone wants to test their own skills)
 
It's the Americans who always make me chuckle

They still work in ozs and gallons so working out how many ounces of oil to add to a gallon of "gas" is real feat of arithmetic gymnastics .

( 2.56 if anyone wants to test their own skills)

Yes .... agreed (assuming 50:1)!
 
Strictly speaking, if you want a total of 30 litres once mixed, you would need about:

30 * 1/51 = 0.588 litres of oil

and

30* 50/51 = 29.412 litres of petrol.

Yeah, yeah, I agree, it will make booger all difference here, but sometimes in life correct calculations are critical

What you have quoted is 49:1, the spec is 50:1 so the volumes are addative and you do end up with 5.1l if you take 5l of fuel and add oil to it.

Edit, If you can stop the pump bang on 5.0l, or even 4.95l, while watching to make sure the can doesn't froth out at the same time you are a better man than me.

Did you know that 6l of fuel will fit in a 5l plastic can, but there isn't much room for oil!

:)
 
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What you have quoted is 49:1, the spec is 50:1 so the volumes are addative and you do end up with 5.1l if you take 5l of fuel and add oil to it.

:)

No. I've quoted a ratio of 50: 1 for a total mix of 30 litres (which is what the op was asking about).

ie 29.412 / .588 = 50 (give or take a tiny roundings error).

Ie the volume of petrol is 50 times the volume of oil, and the total of the two is 30 litres.

I agree, of course, that 30 litres of petrol to 0.6 litres of oil is also a 50:1 mix (30 / 0.6 = 50), but that isn't quite what the op asked (you end up with 30.6 litres, not 30.0).

Q.E.D.
 
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I got it wrong OK.

I'm used to working out 5l of a 2% solution (say) @ work but, 50:1 isn't a 2% solution, which is what I was trying to point out.

Happen I should just sit here and look stupid instead of opening my gob and confirming it.
 
I remember in the past having 2-stroke oil in a bottle whereby you loosened the caps and just squeezed the bottle until the correct measured amount was pushed up into a small pouring chamber.. then after closing the main lid, taking the small lid off, just the small amount in the measuring chamber would be poured.

Something like this.. Clean and simple.

http://www.frjonesandson.co.uk/products-page/stihl/oils-lubricants1/stihl-two-stroke-hp-super-1-litre-oil-measure-bottle/

Strange that 2-stroke oil isn't sold in this packaging more often.

Can you buy these bottles on their own?
 
FWIW - My diesel treatment comes in a measuring bottle like the above. So easy to just put a measured 5ml in.... :)

But it'll take years before I have an empty container for 2-stroke measuring. :(
 
I remember in the past having 2-stroke oil in a bottle whereby you loosened the caps and just squeezed the bottle until the correct measured amount was pushed up into a small pouring chamber.. then after closing the main lid, taking the small lid off, just the small amount in the measuring chamber would be poured.

Something like this.. Clean and simple.

http://www.frjonesandson.co.uk/prod...o-stroke-hp-super-1-litre-oil-measure-bottle/

Strange that 2-stroke oil isn't sold in this packaging more often.

Can you buy these bottles on their own?

first lot oil I bought came in one of these, but second lot was just a straight container... having said that I never used the little measuring bit.. I had a specially marked pot a la VicS

dscf0081_1.jpg
 
Looks like that oil in your photo does indeed have the measuring marks... Perfect :)

I usually add oil whilst on board.. so didn't want to end up with extra measuring pots lying around (and having to wipe them clean after use).
 
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