2 stroke mixture?
 

me and my mate are having dispute over 2 stroke mixture. at 25-1 mix i say it's 25 parts fuel to 1 part oil. my mate reckons its 25ml of oil in 1 liter of fuel? please sort this out for us and help him before he blows up his sons scrambler!

25 parts of fuel to 1 part oil is the correct mixture .
25 ml oil in 1liter of fuel would be 40:1 .

Correct Ratio
 

Most Chain Saws (and most modern 2ST engines) use 40:1 Ratio Fuel :Oil
25:1 Ratio Fuel :Oil is for old engines and makes them very smoky
More oil (in the mix) = longer piston/ring life but suffer oiled up plugs if not running at design RPM
Less oil = more power and more wear but if the engine has a Chrome bore does not lower engine life
So the answer is run the 40:1 mix with plated bores safely if steel bore engine will wear faster but give more power
If the engine is run at low revs for long periods then some were in between is right!
Joe

2 stroke mix
 

If you like your crankshaft run a richer oil mixture. The top end will run on a lean mixture of oil but the bottom end likes oil. Sparkplugs are cheap. The type and quality of oil also makes a vast difference.

not regular.

Good luck, have fun.

Well you can go as lean as 100:1 with modern high performance synthetic oil but that wasn't the question .
The question was how to work out a 25:1 fuel to oil mixture ,which by the way is 40 ml to one litre of fuel .
My first bike ran a 16:1 mixture [ half a pint to a gallon - a British gallon as well by gad ] and was delightfully smokey helped by a bit of castor racing oil ,bloody marvellous smell too .