tohatsu Outboard Problem

[WolfgangSeaLife]

My tohatsu 5 2 HP, 2 stroke, internal and external tank, using external tank, starts with starter spray, then runs with choke just 1/8" open and throttle 1/2.
Any more or less choke and it stalls.
gas has been standing for a year, I added gas cleaner.
carburator seems clean, I took it apart, also sprayed carburator cleaner in repeatedly while running it for 30 minutes. No change. Repeated this twice.

Fuel line seems ok, fuel filter ok. carburator had gas, I opened drain screw to check.
Next I will get new gas, but don't know how to get rid of the old gas. Or drain the tank and clean the gas and refill???

Any ideas?
Wolfgang

[Paul L]

Definitely start with new fuel. If this doesn't get you going, then you will probably need to clean the carburetor jets.

[belizesailor]

Originally Posted by Paul L

Definitely start with new fuel. If this doesn't get you going, then you will probably need to clean the carburetor jets.

Agree. Sounds like a carb/fuel issue to me.

Dispose of all the fuel in the tank. Drain the fuel line. Run engine till it dies. Fill with fresh fuel. If that doesnt fix it, then another carb clean is in order. Careful when cleaning jets, dont damage the orfices. Use carb cleaner with a spray tube (the little red tubes) and shoot it down each circuit (internal channels) in the carb. Wear safety glases when you do this...it can easily spray back toward you...you do NOT want that stuff in your eyes.

Also, check the diaphram in the fuel pump. Could be a fuel delivery issue too. Clean the pump as well.

[WolfgangSeaLife]

Thank you both. It worked. One should have very thin wires in the toolbox for carburator cleaning. And used plenty of carb cleaner.
Also the gas must be exchanged and all fuel lines drained.
Running well now
Wolfgang

[a64pilot]

A lot of people say that you can ruin a Jet with a wire, unless your very careful.
However I have found that monofilament fishing line works almost as well, and I would be surprised if you could ruin a jet with it.

[kmacdonald]

Take the carb apart and soak it overnight in carb cleaner. Spraying it with carb cleaner won't get it done.

[nhschneider]

I had the exact same problem with the exact same engine. I went so far as to buy an ultrasonic cleaner large enough to fit the carburetor into. Still wouldn't run right. A friend of mine who also has the same engine and had the same problem suggested to take the emergency stop switch apart and clean it. Even though the engine was relatively new and I could see no problem with the emergency stop switch, the engine ran fine after that. Go figure.

Fair winds and calm seas.

[kmacdonald]

You can buy a new carb for a lot of outboards really cheap-----almost as cheap as the carb cleaned. Google the carb part number and see what falls from the trees.

[Bean Counter]

Another trick that sometimes works, with fresh fuel and carb cleaner additive in the fuel, run engine as fast as it will go, pushing the dinghy if necessary, then pull choke all the way out. Before it dies push choke back in. Keep doing this until clogged jets get cleared. I do this as soon as the engine starts playing up. Apparently Tohatsu/Mercury/Nissan have very fine jets and clog easily.

[a64pilot]

Originally Posted by nhschneider

I had the exact same problem with the exact same engine. I went so far as to buy an ultrasonic cleaner large enough to fit the carburetor into. Still wouldn't run right. A friend of mine who also has the same engine and had the same problem suggested to take the emergency stop switch apart and clean it. Even though the engine was relatively new and I could see no problem with the emergency stop switch, the engine ran fine after that. Go figure.



Fair winds and calm seas.

Many years ago I bought what was then the fastest sport bike made.
A Yamaha FJ 1100. I had previously been a professional motorcycle drag racer so I liked fast bikes, then after I had the bike for awhile it began to “bust up” at higher RPM, meaning misfire.
I went through everything, plugs, carburetors, coils, the ECU, and nothing would fix it.
Finally one day I realized the bike had a side stand kill switch. Put the bike in gear with the side stand down and it would kill the ignition.
Well guess what, at high RPM the vibration was apparently actuating that **** switch and the ignition would miss.
I verified the failure by unplugging the switch.
Making sure the kill switch isn’t the issue can save you all kinds of worry if it is.

[Paul L]

Originally Posted by a64pilot

A lot of people say that you can ruin a Jet with a wire, unless your very careful.
However I have found that monofilament fishing line works almost as well, and I would be surprised if you could ruin a jet with it.

I use a wood toothpick that I whittle the end sharp. Too soft to do damage.

[stnick]

i had the same problem withe same model engine. Looks like at one time I put reg gas in the tank and it ate the inside of the fuel lines made a black powder like that clogged the baby jets. I replaced the fuel lines with better quality tubing cleaned and used a compressor to blow the jets. Now it runs fine Non ethanol fuel with some marvel mystery oil in it and out board oil and the anti water liquid. Now she runs !! The jets are in my opinion to small. I used a needle to clean them out !

[belizesailor]

Originally Posted by a64pilot

A lot of people say that you can ruin a Jet with a wire, unless your very careful.
However I have found that monofilament fishing line works almost as well, and I would be surprised if you could ruin a jet with it.

Good idea.

[sailjumanji]

Sometimes spray just doesn't clear the clog. And some of the parts don't react well to being soaked in a strong cleaner - it will dry out the rubber O-rings, gaskets, etc. - so be careful. I always prod through each of the jets (holes). Either pull a wire off of a wire brush to use, or use one of these kits:

https://www.blazenauto.com/store/4a-...f729838042baa0

It has multiple small gauge wires that are stiff, and have a little serration. Don't go crazy with them - find the right size one and just gently pass through. On my old motors - and using gas with ethanol - I got very good at cleaning carbs, even underway on trips a couple of times. Probably cleaning each carb 2-3 times per year. When I replaced the motors in 2012, I started using ethanol-free gas as much as possible and have only cleaned the carbs a couple of times since.

Oh, and there are the obvious jets that need prodding to clear, and there are also very fine holes under the removable plate of the carb that are usually the culprit. Make sure you poke through each of those.

These tools are cheap. Buy several and give them to your friends. If they run outboards, they will appreciate having them someday.

[a64pilot]

That tool is an acetylene torch cleaning tool, as such those are round files, meant to remove the soft metal of a torch tip after you file the end flat.
They will most assuredly open up a jet and change the mixture ratio.