I am just starting this topic, please add to it.

If you have a choice never use fuel with ethanol added.
No benefit to use premium fuel.
Be accurate when mixing oil and petrol.
Do not add more oil than is specified.
If you must store fuel, keep the container as full as possible before use.
Mix the oil and petrol only when you are ready to use it.
Stored mixed two stroke fuel, only has thirty days before it starts to deteriorate.
Wipe the top of the fuel container clean before pouring fuel into the tank.
Use synthetic oil rather than mineral oil.
Better to run the motor dry than leave fuel in the tank for extended periods.

MarcoP said..
Timely topic for me @Bundeenabouy. My relatively new 3hp runs, but has been gutless recently. It has struggled to get the RIB up on the plane, when it used to. And when it's been under full revs for a couple of minutes it sometimes slowly dies like it is choking because the breather cap is closed. I've been wondering if it's because I break every rule you listed.
My favourite trick is to fill one of my two 10ltr jerry cans and add oil at the bowser, but months later when it's time to crack the lid on the full jerry, I wonder if there's oil and add a bit more just in case. So, the question is, where do I dump stale fuel? The question I've been wanting to ask for a couple of months is, how can I tell if my fuel has had oil added? Colour is a guide, but not definitive. And oily appearance is likewise. is there a sure-fire trick?

I used to do a similar thing to you, but we all hate a engine that does not run well, or worse will not start at all.
For me its worth sticking to the rules and my motor should outlast me.
Its like putting money in the bank. It will be there when you need it.

It will only take you an hour to service the carburettor, and it sounds and feels great when you have tuned it right.

You can learn a lot about your petrol oil mix from looking at the spark plug.

Good luck with it.

my father taught me to turn the fuel off and let the two stoke engine stop that way .

2 stroke mix can feel oily in your fingertips when you compare it to unmixed fuel.
Look for engine manufacturers details to determine the grade of fuel and the oil ratio.
Spark plug reading tells more about the air /fuel ratio so you shouldn't alter oil ratios to get a cleaner plug.
Cylinder head geometry and ignition timing are designed around a specific fuel grade,,,Higher octane rating fuels wont necessarily perform better in an engine that is designed to burn a fuel of a lower rating with a specific oil ratio and,,,even changing oil/fuel ratio changes compression therefore changes the way the fuel burns.
Don't believe that running the engine out of fuel to empty the fuel bowl can seize the engine, because of lack of oil lubrication,, as is sometimes circulated, That myth comes about from the shock cooling phenomena of when a two stroke runs out of fuel and the engine continues to be over driven by the transmission,,, the temperature of the engine cylinder drops rapidly altering clearances between moving parts within the engine resulting in seizure. more common in air cooled HP engines. (and air cooled aircraft engines when throttled right back during decent).

JAKE123 said..
I have heard that using old two stroke mix in your car engine can mess with the O2 sensor. I would avoid it and use the old fuel elsewhere. You might be able to get away with it if it is just a small amount in each tank that is ultimately up to you.

I would advocate buying a syringe or mixer bottle. Fill Jerry to take with you if its a longer trip and only mix small amounts of 2 stroke fuel as required. you can then use the unmixed fuel in your car if needed.

As for ethanol - it is hydroscopic. it is probably fine in the short term but in a humid environment it might absorb water if stored for a lengthy period. Check the owners manual - i remember my last 2 stroke outboard which was a tohatsu/merc said no ethanol, in the owners manual.

I like the idea of using a syringe for oil measurement accuracy, certainly less messy

I try to buy 91 from Caltex, I think it probably has less ethanol but I have no proof of that. Never use higher than 91. I have tried synthetic oil but I think it's just dearer and works the same as mineral. Mix the oil at the lean end of the range. I used 40:1 with an older Evenrude 15

Yamaha sell a 2 stroke measuring bottle that has graduation on the side to shows you how much oil to put with how much fuel for 25,50 and 100 to 1

www.huntsmarine.com.au/products/yamaha-2-stroke-oil-measure-bottle-pn-oil-measu-re

Regards Don

Bundeenabuoy said..
I am just starting this topic, please add to it.

If you have a choice never use fuel with ethanol added.
No benefit to use premium fuel.
Be accurate when mixing oil and petrol.
Do not add more oil than is specified.
If you must store fuel, keep the container as full as possible before use.
Mix the oil and petrol only when you are ready to use it.
Stored mixed two stroke fuel, only has thirty days before it starts to deteriorate.
Wipe the top of the fuel container clean before pouring fuel into the tank.
Use synthetic oil rather than mineral oil.
Better to run the motor dry than leave fuel in the tank for extended periods.

May I just add after running a 9.8 HP Tohatsu 2 stroke for the last 7 years as my cruising catamarans main engine and a 2.5HP 2 stroke as the dinghy motor for the last 20 years.
1
NEVER had a problem with ethanol in fuel. We cary 180 litres in 20L jerry cans. Fuel can be over 12 months old and still runs fine.
2
We pre-mix fuel with oil as soon as we buy it and before it goes aboard the boat. Its to hard at 2 AM to try and work out if the fuel has oil in it or not.
3
If we are leaving the boat for a month or two we will run the fuel out of the Carby by disconnecting the fuel line and letting the motor starve.
4
Learn how to strip your Carby and clean. Capsizing the dinghy in shore breaks on the South Coast makes this knowledge essential.
We have never bothered with a dedicated fuel filter /water sepperation system on the 9.8 and have used fuel from some pretty remote and dodgy suppliers with out issues. A 6 month strip and clean keeps things purring ( well more a ring ding dinging)

gwiongwion said..

1
NEVER had a problem with ethanol in fuel. We cary 180 litres in 20L jerry cans. Fuel can be over 12 months old and still runs fine.

Yes it's best not to worry about ethanol. Any 91 you buy could have up to 9% of ethanol. The local garage in this South Coast village is an independent and they are flat out selling 91 to fishermen on their way offshore. I have never heard of any complaints. Ethanol is cheaper than petrol and it would be naive to think there is no ethanol in the stuff we buy. The ethanol factory is about 15ks from my place.

Write on side of container the date fuel was put in it and date oil was put in it. Helps with Alzheimer's.
We use similar colour coding as Sunycoastguy, but add black for water.
When its stale, dont really know how to judge, that but after a year, in order to dispose of 4 litres of unknown I tried putting it in my 2004 Ford Terror while it had a nearly full tank of normal unleaded and no problem. The Terror didn't blink.
IT would be great to have an easy way to tell if the fuel had the oil in it or not. So far I tipped a bit in a glass and looked at its colour but the fuel itself comes in different colours. I will try the tissue idea above.

samsturdy said..
My Mercury 3.3 used to be hopeless, It would start on second pull but wouldn't accelerate and wanted to stop all
the time. I had to coax it along until it had run for 5 or 6 minutes, really annoying. The reason, apparently is because I
drain the carby. I took the engine to the service guy and complained about it and he said to leave the carby full.
So that's what I do now and there's no more trouble. Doesn't seem logical to me....but it works.

That's annoying, but better than having issues, and good you solved the problem.

I used to have a 5hp Mercury two stroke for a while and l developed a routine of systematically doing the same procedure every time. I never ever kept petrol on board without mixing in the oil. Period.

After l got rid of it, for it was too heavy to lift it every time onto the holder plate on the stern, l replaced it with a four stroke 2hp Honda and never looked back. The mixing of oil was over and l never used adulterated - l mean the alcoholized fuels or E10 or whatever they call it - just clean unleaded usu 95 octane or so.

(The misguided use of the E10 concoction in my bike [DR650] caused the carby to gum up in a fashion never seen before. After a full carby service and replacement of all hoses and seals which became soft and gooey from that chemical soup called E10, the bike runs fine on plain unleaded, ever since.)

The little Honda always started second pull even after months of sleep. It lived on the stern with a cover over it. It was not necessary to drain the carby when stopped.

If any of you got problems with a two stroke and you used E10 in it before, you are bound to pull the carby down and clean it thoroughly with special attention to the float needle and bowl, and replacing all filters and rubber seals and hoses because they are eaten away by the WRONG FUEL as one never suppose to use E10 in an outboard motor! Despite all hype and bull!

Even if there are no visible signs of deterioration on fuel hoses they must be replaced because the damage has been done already by the chemical soup they call FUEL!?