Re: Tohatsu troubles
If you suspect the fuel is the problem here is a quick easy way to check it. It will take about 15 minutes to do so.
First disconnect the fuel line from the carb and drain some fuel into a container, I prefer to use a glass jar, about a 1/2 to a cup is all that you need to drain. Then set that aside and let it set without being agitated. After the fuel has set then look at the bottom of the jar from the top. If there is water in the fuel you will be able to see it.
If there is not water in the fuel, tip the tank so you can look in the fuel fill cap and let it set for a bit and see if there is water in it, water will always go to the lowest point so make sure you are looking in the corner and it is the lowest point, prop the tank up if you need to.
when you have ruled out the water in the fuel, the next step is to clean the jet at the bottom of the fuel bowl. First drain the bowl and then remove it, at the bottom of the lowest part of the pickup is a brass piece, use a flat tipped screwdriver to remove it and check to see if it is clear. I will generally run a small wire through it just to be sure and shoot some carb clearer through it. Even a small piece of debris or dirt will make the engine run rough or not even start.
I use a 3.5 tohatsu engine on my dinghy and have had the same problems as described and this is what I have found the problem to be.
Also I use just regular fuel from the gas station the 87 octane type that has ethanol in it. I have found that it works fine but it does take a toll on the fuel line after about a year so I replace it. I do not put any additives in the fuel, the trick is to use the fuel with in a 6 month or less period.
Hopefully this will help in solving your problem, fair winds and the best of sailing to you.