Filling your 2stroke tank

[Laundryman]

Ive been reading the threads on the 2 stroke versus 4. I have a tiny Mercury 3.3 2t that runs on 100-1 mix. Does everyone religiously measure out the mix or do you make an educated guess, ( with a bit for luck)? Do you keep your fuel pre mixed or do you mix at the point of fill? What do you use to measure accurately if you do please? Thanks. Alan

 

[sailorman]

Ive been reading the threads on the 2 stroke versus 4. I have a tiny Mercury 3.3 2t that runs on 100-1 mix. Does everyone religiously measure out the mix or do you make an educated guess, ( with a bit for luck)? Do you keep your fuel pre mixed or do you mix at the point of fill? What do you use to measure accurately if you do please? Thanks. Alan

always measure & your engine will last longer on 50>1 too

 

[Tugw]

I have two engines,i keep my fuel ready mixed in one of those plastic cans from Halfords.(not on the boat) I use and old cooks measuring cup for the quantity but i dont neasure exactly.been doing it for years like this and so far no probs.

 

[SeaStu1]

When l had 2 strokes l used to measure out the oil, although going over a little never made any difference. I always used to premix in a petrol container as l thought it was better trying to do it in the garage rather than on a rolling sea! Most 2 stroke oil bottles have measurements on the side of the bottle as a guide.

 

[lw395]

I mix 5 litres at a time.
Engine is nominally 100:1, but I use 50% extra.
So if I'm a bit out, I'm unlikely to either foul the plug or be less than 100:1.

I have a small bottle for the oil which has lots of calibrations on it, I refill that little bottle from a big can, as a mate of mine buys 2T oil in much bigger quantities.
So I can judge the 75cc quite well.

I would not want to have the mix much further out than say 50:1 to 120:1 on a 100:1 engine.

I mix the fuel in a 5 litre can, then top up the motor before every use, as running out in the middle of Portsmouth Harbour does not make you popular!

I have one can which is always clean fuel and another which is mix. You need a system to know as double dosing with oil or using neat fuel must be avoided.

 

[cliff]

What do you use to measure accurately if you do please? Thanks. Alan

I use one of these - easy to use and no confusion as to whether or not a can is neat fuel or 2t mix.

 

[davidpbo]

I dose a 5L petrol can with 2st oil using either the bottle, a water bottle for hampsters/gerbils with calibrations or a syringe then fill with 5L of petrol as measured by pump.

 

[John100156]

Take plastic petrol container, fill near to top, take note of litres on petrol pump say 5.5, multiply by 20 (for 50:1) thats 110ml of oil required (5500/50).

Use one of those cheap little plastic measuring jugs that SWMBO will have to fill up her steam iron (assuming it has graduations on the side) to measure in the required amount of 2T oil...! Mind you those large graduated syringes are also good...!

Good shake rattle and roll (container that is) and fill your boots or better still the tank! If there's any mix left in the container mark it up: 2T MIX

Or just use the graduated 2T oil container...

Remember to keep the small measuring jug and some 2T oil in the tender, then if you run out of fuel you can always get some from a passing 4T......

 

[maxi77]

When I had an outboard as main propulsion I carried petrol unmixed in 5ltr cans and the oil i 100ml bottles. One of each in the fuel tank and a good shake. I still keep several 100ml bottles of outboard oil so that dosing a 5ltr can for the dinghy outboard is 'simples'. The trick is knowing whi 5ltr can has been dosed

 

[VicS]

Ive been reading the threads on the 2 stroke versus 4. I have a tiny Mercury 3.3 2t that runs on 100-1 mix. Does everyone religiously measure out the mix or do you make an educated guess, ( with a bit for luck)? Do you keep your fuel pre mixed or do you mix at the point of fill? What do you use to measure accurately if you do please? Thanks. Alan

Mostly I mix as required. At home I mix small volumes to top up the Seagull tank, the Flymo tank, the "big" lawnmower tank as required because they all use different ratios . The Seagull of course also uses a different oil to the mowers.

On the boat I keep unmixed fuel, when I keep spare fuel, but mix oil with it 5 litres at a time when required.

Dont guess the volume of oil ....... All my working life i have measured volumes of liquids and even with that experience I'd not feel confident enough to guess the volume of oil.

I use plastic conical laboratory measures for the oil and a plastic measuring jug for small volumes of petrol.

There is a small (100 ml) conical measure in the garden shed where the petrol is stored and a larger one on the boat.

When ever possible I use a funnel with gauze filter to put the fuel in the tanks.

Id run the Merc on a more oily mix than 100:1. If it does not like 50:1 try 75:1

 

[jwilson]

Ive been reading the threads on the 2 stroke versus 4. I have a tiny Mercury 3.3 2t that runs on 100-1 mix. Does everyone religiously measure out the mix or do you make an educated guess, ( with a bit for luck)? Do you keep your fuel pre mixed or do you mix at the point of fill? What do you use to measure accurately if you do please? Thanks. Alan

The Mercury 3.3 is identical mechanically to the Tohatsu version - which uses 50:1 and 25:1 for running in, if I remember correctly. I run my Mercury 3.3 on 50:1 - measure the oil and put it in an empty can then add petrol at the filling station.

 

[Conachair]

Digital kitchen scales, fill a plastic cup with water to whatever amount of oil is needed then a sharpie mark on the side of another plastic cup at the same height.

Sounds a bit involved but the kitchen scales are used for 2 part paint so all the bits are to hand and takes just a moment.

 

[Lakesailor]

The Mercury 3.3 is identical mechanically to the Tohatsu version - which uses 50:1 and 25:1 for running in, if I remember correctly. I run my Mercury 3.3 on 50:1 - measure the oil and put it in an empty can then add petrol at the filling station.

Yep.
100:1 is a bit thin for a small outboard, what ever it says in the manufacturer's handbook. If you are doing it by eye then you could be running at 125:1 which is way out of bounds.
50:1 is much safer. The damage that may occur at lower mixes can include overheating and main bearing damage. (I bought a secondhand Tohatsu and had to rplace the main bearings as a result of it being run od a low-oil mix.)

Over-oiling may give you a sooty plug.

Your choice.

 

[nigelmercier]

As mentioned in the other thread, I aim to use 50:1, but if there is any doubt that oil has in fact been added to the 2-stroke can, I add even more.

Is there an easy way to test?

 

[ex-Gladys]

One of the points to remember is that water cooled outboards run very cold compared with air cooled 2 strokes like motorbikes, and there is a higher chance of plug oiling on an outboard, although modern electornic ignition does a lot to prevent that

 

[SAWDOC]

Ive been reading the threads on the 2 stroke versus 4. I have a tiny Mercury 3.3 2t that runs on 100-1 mix. Does everyone religiously measure out the mix or do you make an educated guess, ( with a bit for luck)? Do you keep your fuel pre mixed or do you mix at the point of fill? What do you use to measure accurately if you do please? Thanks. Alan

I put 100mm of oil in a large fuel container, using a calibrated jug, and then put in exactly 10 litres of petrol at the local garage. No problem and lasts a good while. Just remember to keep the fuel container air valve closed whne not in use.

 

[prv]

I still keep several 100ml bottles of outboard oil so that dosing a 5ltr can for the dinghy outboard is 'simples'.

I like that idea. In fact I like it so much I've just gone and bought a set of plastic bottles for a couple of quid on eBay.

Pete

 

[John100156]

As mentioned in the other thread, I aim to use 50:1, but if there is any doubt that oil has in fact been added to the 2-stroke can, I add even more.

Is there an easy way to test?

I wouldn't worry too much, in my Mariner manual it's suggests 25:1 for initial running-in, the test is as follows: When you start the motor if you can still see the boat the mixture's OK....

Like the idea of 100ml bottles too.

 

[VicS]

As mentioned in the other thread, I aim to use 50:1, but if there is any doubt that oil has in fact been added to the 2-stroke can, I add even more.

Is there an easy way to test?

Grease spot on some paper perhaps. Qualitative not quantitative .

Difficult to do quantitatively with the equipment most people would have. I'd allow a few cm³ to evaporate then weigh the oil that remains.

 

[mcframe]

I have a small bottle for the oil which has lots of calibrations on it, I refill that little bottle from a big can, as a mate of mine buys 2T oil in much bigger quantities.
So I can judge the 75cc quite well.

I use a 100ml shampoo bottle (Lush, IIRC) to provide a single dose for a 5l petrol can, and fill it up from larger oil bottles after each mix. I always mix the petrol can as soon as it comes onboard . Any end-of-season dregs get diluted in my motorbikes - which are syphoned to provide the start-of-season fresh unmixed petrol ;-)
(Diesel car & swinging mooring, so *black* jerry can gets filled up at same time as car and is used to top-up boat tank.)