Oil to fuel ratio.Whats correct?

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ddm and onb say to use 25-1 so I always went with that. I tried the 40-1 mix and didn't notice any increase in power. So I stay on the safe side. oil and gas are cheap, engines aren't
 
I 3rd that!:)

You never go by an oil manufactures recommendations. I say that because Stihl oil is 50:1 which is what they are recommending for their 2 stroke motors in their products. If you look at others they also make oil or private label others oil and recommend anything from 25:1 to 50:1. They know what their engine tolerances are and what will work for the rpms of their products.
Amsoil tells me to run Amsoil Saber Pro at 100:1, some are trying it, me, no way 25:1.:no:

Stay with the engine manufactures recommendations.:)
 
Some boat guys did a test years back on oil ratios and got more out of there motor the more oil they used. NOt exactly the same usage as our motors but shows it just the same.
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BTB, I'd heard that sometime ago myself and refused to believe it until I met up with a local guy that modifies motors for boats as well. He explained that with more oil, the motor cant burn it up all fast enough so some of it goes to the top of the piston which then create just a little more compression in the cylinder. If he'd said less oil, theres no way I'd tried it but more oil is always better than not enough. I tried 18/1 and it runs great. The motor's a little more sluggish on the bottom but as some know, I really don't care for bottom. It actually seemed to build a little more on the top end.
 
Just been looking to see what 2 stroke oil you all use and found this thread.

Can't believe the amount of long time RC'ers who have got their wires crossed over the fuel mix.

25/1 is not a percentage, it is parts per part; and not 25ml to 1ltr

If you want to run @ 25/1 the mixture should be; 40ml of oil to 1000ml (1ltr) fuel.
You get the ratio by dividing the 1000ml (1ltr) by 25 = 40ml

80ml of oil to 2ltr
120ml of oil to 3ltr
160ml of oil to 4ltr
200ml of oil to 5ltr etc etc.

Just thought i'd bring the thread back into play for anyone who's new/confused about their fuel mix. ;)
 
jackobyte said:
Just been looking to see what 2 stroke oil you all use and found this thread.

Can't believe the amount of long time RC'ers who have got their wires crossed over the fuel mix.

25/1 is not a percentage, it is parts per part; and not 25ml to 1ltr

If you want to run @ 25/1 the mixture should be; 40ml of oil to 1000ml (1ltr) fuel.
You get the ratio by dividing the 1000ml (1ltr) by 25 = 40ml

80ml of oil to 2ltr
120ml of oil to 3ltr
160ml of oil to 4ltr
200ml of oil to 5ltr etc etc.

Just thought i'd bring the thread back into play for anyone who's new/confused about their fuel mix. ;)
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Nice one Jackobyte.

I have two types of synthetic oil both are Rock Oil (Warrington) made products for King Cobra and both give different advice on the label. The older bottle advises 30ml to 1 litre of fuel while the newer bottle gives 35ml to 1 litre of fuel. Knowing Rock Oil as I do (they are a customer of mine as are Millers Oil, Morris Lubricants etc.) They actually bench tested an rc 2 stroke engine to get the best possible blend to run in the higher performance engines under various load conditions. In fact I believe they even had a Stevo modified engine on test for the newer of the oils that I am running in my V4, but don't quote me on that.

The companies named above all have a product range of Lubricants specifically designed for 2 stroke engines, Rock Oil and Millers are very active in most forms of motorsport form bikes to cars so they stand by their products.

Therefore, for the safety of your engine just follow the guide on the bottle, lessening the amount of oil in your fuel may give you a slight gain but it will come at the detrement of engine life and in most cases you will be hard pushed to really notice the gain.
 
Super654 said:
DC...125ml to 5 litres is 25/1....25ml to 1 litre...you are rich mate...
I used to run 20/1...20ml to 1 litre...100ml to 5 litre...in winter and 25/1 in sumer when engines get hoter...
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I was just reading through the start of this thread & 125ml of oil to 5L of fuel is a 40-1 mix so that is lean. 20ml of oil to 1L fuel is a 50-1 mix so even leaner. Jacko has clarified the oil content in his post and they are correct for a 25-1 mix. I think you need to richen yours up a tad Brad.
 
I can't be bothered trying to do math. I put 100 ml of oil in then pump 2.5 litres into the gas can... rest goes into the van... good thing I don't mix it like my detailing chemicals. that's all eyeballed hehe.
 
I'm a chemist by profession and work with ratios and calculations every day of my working life - doing this as home is a 'busman's holiday' so I simply bought one of the 1L mixing bottles you'll find on Ebay.
They permit the preparation of 1L of mixed fuel / oil at 25:1, 32:1 or 40:1.

Previously it was 'considered safe' for a 40:1, then everyone started realising not all oil was the same, and more and more engines were 'wearing out prematurely' so 32:1 was selected as the default.
Now, everyone tends to 'add that little safety margin' and go for 25:1.

As I've been told in the past, the oil isn't going anywhere, but if you've left your 'ride' for a while, 'shake it up' (however possible !!) to remix, as the oil can sometimes settle out.
Perhaps even empty, remix and refill, or simply replace with fresh if in doubt.

It is possible that as the petrol is much more volatile than the oil, that the proportion of oil in the mix increases with time, basically as the petrol slowly volatilises through the breather.

Al.
 
1 litre isn't enough lol. I take 3 sometimes 4 rc's to play and have to fill all the tanks at least once. not to mention someone will run out and need to borrow some... they cheap out and only mix a litre ;)
 
someone should do a test and see what happens to a 2t mix over weeks in average conditions. during summer I don't notice it as much but this winter ive noticed ive had to play around with needles quite a bit and starting to wonder if its because my 2t mix is being stored a bit longer in winter.
 
Super654 said:
BTB, this is now confussing me...lol...what is 100ml to 5 litres-20ml to 1 litre..20/1 in my eyes
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Your ratio at the moment is:-
1000ml (1L) fuel divide by 20ml oil = 50 so a 50:1 mix (50 times more fuel than oil or 50 parts fuel to 1 part oil)

If you divide the amount of fuel you are using by the ratio you want to achieve it will give you the quantity of oil you need to add for each ratio.

A 25:1 mix would be:-
1000ml (1L) fuel divide by 25 = 40ml oil

Or to work out how much oil you need for a 25:1 mix using 5L:-
5000ml (5L) fuel divide by 25 = 200ml oil

It works the same for other ratios eg a 32:1 mix is.......:-
5000ml (5L) fuel divide by 32 = 156ml oil

.......and other quantities of fuel:-
3000ml (3L) fuel divide by 32 = 94ml oil

Hope this helps bud ;)
 
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fuel mixture wrong during breakin info

hi all can you please give some information

I am new to 1/5 2 stroke buggies and managed to mess up my fuel oil ratio

I used 1ltr of fuel and 25ml of oil thinking this was 25:1 now I realise I read it wrong and it should have been 1 litre fuel to 40ml oil

luckily or I hope, I only had engine idle for 15min had a break for half hour then another 15min idle as I am heat cycling engine before slowly running car

will this have caused any damage to my engine with me not putting enough oil in ?

any info be much appreciated
 
Hi Steve,

Firstly, WELCOME to LSF.
Second, not knowing how much fuel is used / is left, it would be easier to dispose of the incorrect mix - take care how you do so. Could use it for cleaning possibly.
Third - mix a new batch as indicated in the thread - Pipeous and Dwarfy have explained well.

Al.
 
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