what 2 stroke mix to use?

geordie_richie · 29 April 2011, 20:56

Hi sorry for asking this cos it will probably sound daft to most you guys!
Ive just got a 40 hp mariner 2 stroke looks late 80`s early 90`s and not sure what the mix would be?
The guy i got it off said 100-1?
so what would 100-1 be in ml-litres measurments?
when i used to have motorbikes i used to put 25 ml to every litre, Any help would be greatly appreciated.
Many Thanks
Richie

kerny · 29 April 2011, 21:04

Hi mate and welcome, if its 100 to 1 a 22ltr tank will take 1/2 ltr of oil

markg · 29 April 2011, 21:29

100-1 would be 10ml per litre, i have always used it a bit stronger than that, has not done any harm
220ml in a 22ltr tank would be 100-1, half a litre is probably what i would stick in it

actions · 29 April 2011, 21:36

1 litre = 1000 millitres, so 100 to 1 mix makes it 10ml per litre.

Just make sure its 100:1 as i think a few will say 50:1 is better for the engine but others on here will clarify that.

Make sure its a decent marine outboard oil too, only use TCW3 oil.

geordie_richie · 29 April 2011, 21:40

Thanks for that guys, ive read up and a lot seem to say 50-1 so i think ill pop up to the shop tomorrow and see if they can check for me just to be safe.
Thanks again
Richie

wavelength · 29 April 2011, 22:25

they were 50:1 despite being identical to the yamaha 40 which was 100:1,
My boating buddy had the yam and I had the mariner. We used to run both at around 50:1, on the grounds that if 100 was good then 50 is better.

geordie_richie · 29 April 2011, 22:39

yeh ive read a lot that the yams should be 50-1, really if i put 50-1 it cant harm it just make it a bit smokey!

actions · 29 April 2011, 22:49

Quote:

Originally Posted by geordie_richie

yeh ive read a lot that the yams should be 50-1, really if i put 50-1 it cant harm it just make it a bit smokey!

Exactly, 50:1 will ensure the engine is getting all the lube it needs...... and it wouldnt be a two stroke without the smoke.

Nos4r2 · 29 April 2011, 23:41

Is it a 2 cylinder or a 3 cylinder?

2cyl is a Yamaha based motor and is 100:1, 3cyl is 50:1

Nos4r2 · 29 April 2011, 23:43

Quote:

Originally Posted by kerny

Hi mate and welcome, if its 100 to 1 a 22ltr tank will take 1/2 ltr of oil

No it's not-that's 44:1 if you use 1/2 litre to 22 litres.

kerny · 30 April 2011, 00:55

Quote:

Originally Posted by Nos4r2

No it's not-that's 44:1 if you use 1/2 litre to 22 litres.

I stand corrected,,, but I will still put 1/2 ltr in mine. I can't be arsed using a syringe.lol

Nos4r2 · 30 April 2011, 04:24

Quote:

Originally Posted by kerny

I stand corrected,,, but I will still put 1/2 ltr in mine. I can't be arsed using a syringe.lol

Mark up a coke bottle. It's better than oiling your engine up and making it run weak.

uncle al · 30 April 2011, 10:58

40hp mar/merc forget the 100.1 decal remove and put it in the dustbin, always run at 50.1 a little bit of extra oil will not hurt and always run a little bit to rich, NEVER run a bit lean maybe good for fuel consuption but you will shorten the life of the p/h.

nugent · 30 April 2011, 18:37

so 50:1 is 25ml of oil per ltr fuel .............. yes?

nugent · 30 April 2011, 19:02

ah haaaaaaaaa

http://www.csgnetwork.com/oilfuelcalc.html

20ml per ltr

wavelength · 30 April 2011, 21:25

Quote:

2cyl is a Yamaha based motor and is 100:1

no it was a 2cyl yamaha based motor and 50:1 when I had one as per my previous post, despite 2cyl yams of that vintage being badged at 100:1 Stick 50:1 in and it'll be fine. Mine never let me down in 15years of year round use all round the uk and on three different boats. Stick 100:1 in and it would prob still be ok but we never ran any of them at that ratio no matter what the badge on it- its an awfully small amount of oil in an engine and more certainly aint gonna hurt, make it smoke or foul the plugs but it will ensure some decent lubrication.
Oh I do miss the smell of two stroke in the morning!

geordie_richie · 30 April 2011, 22:27

Thanks guys, Ive been out on it all day today running it 50-1, 100ml per gallon and it ran well all day!
Regards Richie

wavelength · 01 May 2011, 20:34

brilliant engines-bombproof-go for ever. Unlike the mercury derived later ones

9D280 · 02 May 2011, 14:46

I guess it depends what you are doing with it. If you spend the whole day pootering about at idle to fish or rescue sailing dinghies, you could get away with a lighter mix.

Bear in mind some of the auto oilers run something like 200:1 at idle!

I will having said that agree with above -if you are running flat out most of the time, 50:1 won't do it any harm.

For what it's worth, when pre- oiling a tank, the thing to remember is that for 50:1, 2% of your tank volume should be oil, so for a

30L tank, you need 600 mL of oil
25L tank, you need 500 mL of oil
22L tank, you need 440 mL of oil
5L tank, you need 100 mL of oil

The down side to this is that you can't use a standard Cola bottle to "pre charge" a 30L tank...