Trying to work out 2 stroke ratio

[Stuart Mecham]

my Merc 50hp is 50-1 mix,

Would 1 gal petrol = 84ml of 2 stoke oil?

Sorry for this daft question, but my math sucks.. lol


Thanks for any help



Stuart

[Pete7]

Stu, suggest you use litres instead it makes the maths easier. We use an small plastic milk bottle as the measuring container to a red can of petrol (22 - 25L depending on type).

Pete

[jools]

I used to use a small plastic measuring jug from Ikea!

I marked the side with various amounts of petrol - ie 5l, 10l, 15l etc. Then when I filled up at the petrol station I just added the appropriate amount of oil.

By marking the measuring jug I didn't have to use my head at the petrol station.

(TomKat has an internal 25l (I think) tank that takes pre-mixed fuel - and I always used to like to go out with a full tank)

Jools

[Bilge Rat]

My Searider has a oil tank at the transom which i just make sure is topped up with oil, then the engine sucks up exactly what it needs to run and injects it into the engine, saves all the measuring and messing about.
Also has an engine cut out if the oil level drops to low, means the engine wont run then.

R

[matiboy]

Instead of telling him what colour your outboard is !

1 gallon = 4.5446 litres

Good converter bellow to bookmark

http://gocanada.about.com/library/nmetric.htm

So in answer to your question at 50:1 I make it 91 ml

As suggested easier to work in litres from the pump , also best to put in the oil first so that when the calculated amount of fuel goes in, it mixes it well.

1 litre fuel = 20 mil
2 litres = 40 mil
5 litres = 100 mil
10 litres = 200 mil

Somebody else confirm this correct before we go blowing his engine up !

[Mike B]

Matiboy,

I agree - spot on

Stuart if the engine is brand new I think you need to double up on the oil for running in. Check in the manual.

Mike

[Daniel]

Originally posted by Bilge Rat
has an engine cut out if the oil level drops to low, means the engine wont run then.R

Interesting you should mention that - encountered a very nice feature on a new (2002 model) Yam 40 the other day...

...low oil DOES NOT prevent engine running, but limits rev's - enough to get you to shore but hopefully reduces any damage through limited oil. Good idea that.

Note: This safety system operates at low oil, not when you run out which could well do no end of bad stuff to a 2-stroke.

[Bilge Rat]

Hi Daniel

No mines an old set up that when the oil goes below a certain point the engine wont run, has caught me already and had me stumped as when i checked there looked like there was still enough oil in the tank until a mechanically minded friend pointed out the low level cut off. This just means carrying a small bottle of 2 stroke in my spares kit on board.

Seems like a really good idea to me to just have the tank and keep it topped with 2 stroke oil and let the engine sort itself out rather than have to measure and guestimate at the petrol station on a rainy night after a full days boating, old addage is keep it simple !!

Just out of interest what would happen if you did get the mix slightly wrong, would it damage the engine ?


R

[Daniel]

From what i am lead to beleive the mix is not that important. Some engines are 50:1 some 100:1 and 'unofficialy' they will both work on 75:1. Most people with pre-mix add a bit for luck anyway, which makes a bit more smoke and i assume looses a bit of power.

Autolube / oil-injection is 100% the way to go, BUT they do go wrong - twice on me. First time ruined the engine (no oil for several hours).

Second time, begining of year, i noticed almost immediatly (no oil going out of tank - sounded different) and the bill was looking HUGE.

Local marine dealer suggested bypassing the whole system and adding oil to the tank - an anoying backwards step but about £1000 less so i'll live, but how i miss autolube...

[David Perry]

Get a multi measure container, marked off in ratios, it shows where to fill the oil to.
I have one, from my previous 2 stroke life, now on 4sEFI...wow!Bids for this oiled beauty..............
Or will swap for 6.5m rib, or some kit...only joking.
I think that you can get the measurers from various chandler outlets.
Will search the net and if I find an outlet, will post.

[David Perry]

visit
http://www.dirtbikestore.co.uk/acata..._Items_68.html