Hey dude, not sure if you were still using the old fuel, but you should drain it and try fresh fuel. Ethanol is hygroscopic, meaning it will absorb water from the air, and if it sits long enough in a humid environment it will take on water causing your engine to run poorly.
I will try that again. It did sit with the ethanol for a month. I did previously drain out the old gas when I cleaned out the carb. But I will do it once more and see what happens.
I was all set to call this a carb issue… BUT, after watching it with the hood off I would start by making sure your choke cable is installed correctly. At 13:02 there is a black cable with a wire coming up from the bottom of the motor to above the carb and attaches to the arm not actuated by the throttle. I believe that goes to the choke and should be in that sleeve on the air intake that sits in front of the carb. If that choke isn’t set properly that may be the cause of your issue. Crossing my fingers for you - there's nothing worse than wanting to go out but the motor doesn't wanna go!
I use regular 87 gas on 6hp tohatsu and have no issues, tohatsu manual it says regular gas 87 is good to use. My new 2023 6hp tohatsu was doing exactly same thing, while on idle RPMS run high and then slows down , and then engine would turn off on its own, i started using external tank and motor never shut down on me so far, also i had issues starting it initially, so i drained oil so it would be on minimal bar and after few runs it started working appropriately, if u put too much oil u can harm your engine per manual, make sure u use marine grade oil, also did you performed break-in properly? These types of rpms shifting happen during break in, so i wonder if you spent enough time breaking it in, my issue resolved after 1. Draining oil to minimum bar 3. Giving about 6+hrs of breaking in time at diff rpms as recommended (running on neutral) 3. Using external tank. After break in period it starts with 1-2 pulls after its primed. Also always run ur motor dry after yoyre done, if you leave gas in tank that can cause starting issues
Ethanol also damages seals in the fuel line and in the carburetor. The stuff really should be banned from being added to fuel, as it is low energy density and increases the amount of fuel that is used, by about double the percentage that is added, e.g. 15% Ethanol, you get about 30% worse fuel Consumption. A total waste of time, money, and energy with the stuff. ☹️
I agree with the rest. Probably fuel related. Water in the fuel would be my first guess. But it is worth mentioning that the plug wires on tohatsu's are often loosely crimped on the plug end. Even brand new. Make sure the plug wires are firmly connected to the plug.
I had the same issue. I had to totally clean the carbonator. I used Ethanol free fuel and still had the issue. Can't any gas sit in the bulb. Super easy fix.
So I think your carb is still messed. I would bring it to a shop. You can also get one of those ultra sonic cleaners off of Amazon to clean the carb. Use 91 octane gas and put fuel stabilizer in it. If your not going to use the motor, run it dry before storage. If you can afford it and your kyak can take the weight, I would get tuhatsu 5 HP propane model (60 lbs) and never worry again about clogged carb.
Problem with propane is it doesn't have the Lube in it engines need. In my friends County, all but one vehicle Propane station have now closed down, probably because people weren't switching back to Gasoline fuel often enough to prevent damage to their engines? 🤔
It sounds like the carburetor is loose. That will cause it to surge for fuel as well as give the engine a false reading of air intake thus your throttle increase without further response. Try tightening your carburetor screws some… if that doesn’t help then a carburetor bowl leak or something. You’re having an air leak problem to your intake.
Also if your fuel tank experiences temperature changes I.E.: becoming wet from sitting in water, then you are probably getting water in the fuel. The fuel will condense when it sees pressure/temperature changes. The fuel will “quench” and produce water. Hope this helps
Hey dude, not sure if you were still using the old fuel, but you should drain it and try fresh fuel. Ethanol is hygroscopic, meaning it will absorb water from the air, and if it sits long enough in a humid environment it will take on water causing your engine to run poorly.
I will try that again. It did sit with the ethanol for a month. I did previously drain out the old gas when I cleaned out the carb. But I will do it once more and see what happens.
Never use ethanol gas in small engines. Only premium fuel with no ethanol.
I was all set to call this a carb issue… BUT, after watching it with the hood off I would start by making sure your choke cable is installed correctly. At 13:02 there is a black cable with a wire coming up from the bottom of the motor to above the carb and attaches to the arm not actuated by the throttle. I believe that goes to the choke and should be in that sleeve on the air intake that sits in front of the carb. If that choke isn’t set properly that may be the cause of your issue. Crossing my fingers for you - there's nothing worse than wanting to go out but the motor doesn't wanna go!
You are right. The choke cable isn't installed correctly.
I ended up fixing that too. Good eye!
Thanks for sharing! Nice story
Glad you enjoyed it!
Did you fixed your motor? Did yoy found the issue that was causing that?
Actually ended up trading it! They fixed it.
Would you dare throw one of the sub 90 lb yamaha 9.9 portable outboards on here?
HA! No way!!!
I use regular 87 gas on 6hp tohatsu and have no issues, tohatsu manual it says regular gas 87 is good to use. My new 2023 6hp tohatsu was doing exactly same thing, while on idle RPMS run high and then slows down , and then engine would turn off on its own, i started using external tank and motor never shut down on me so far, also i had issues starting it initially, so i drained oil so it would be on minimal bar and after few runs it started working appropriately, if u put too much oil u can harm your engine per manual, make sure u use marine grade oil, also did you performed break-in properly? These types of rpms shifting happen during break in, so i wonder if you spent enough time breaking it in, my issue resolved after 1. Draining oil to minimum bar 3. Giving about 6+hrs of breaking in time at diff rpms as recommended (running on neutral) 3. Using external tank. After break in period it starts with 1-2 pulls after its primed. Also always run ur motor dry after yoyre done, if you leave gas in tank that can cause starting issues
Such good info. Thanks so much!
The carb is still dirty from the ethanol, you need to take the jets out of the carb and clean each one by one.
Ethanol is an alcohol, it evaporates with no residue. It does however destroy rubber seals and it's corrosive.
Thanks for the tip!
Ethanol also damages seals in the fuel line and in the carburetor. The stuff really should be banned from being added to fuel, as it is low energy density and increases the amount of fuel that is used, by about double the percentage that is added, e.g. 15% Ethanol, you get about 30% worse fuel Consumption. A total waste of time, money, and energy with the stuff. ☹️
I agree with the rest. Probably fuel related. Water in the fuel would be my first guess. But it is worth mentioning that the plug wires on tohatsu's are often loosely crimped on the plug end. Even brand new. Make sure the plug wires are firmly connected to the plug.
Thanks for the analysis!
I had the same issue. I had to totally clean the carbonator. I used Ethanol free fuel and still had the issue. Can't any gas sit in the bulb. Super easy fix.
Yup! Cleaned and worked well!
So I think your carb is still messed. I would bring it to a shop. You can also get one of those ultra sonic cleaners off of Amazon to clean the carb. Use 91 octane gas and put fuel stabilizer in it. If your not going to use the motor, run it dry before storage.
If you can afford it and your kyak can take the weight, I would get tuhatsu 5 HP propane model (60 lbs) and never worry again about clogged carb.
THANKS FOR THE HELP!
Problem with propane is it doesn't have the Lube in it engines need. In my friends County, all but one vehicle Propane station have now closed down, probably because people weren't switching back to Gasoline fuel often enough to prevent damage to their engines? 🤔
It sounds like the carburetor is loose. That will cause it to surge for fuel as well as give the engine a false reading of air intake thus your throttle increase without further response. Try tightening your carburetor screws some… if that doesn’t help then a carburetor bowl leak or something. You’re having an air leak problem to your intake.
Dirty carb! Thanks for the tips!
Also if your fuel tank experiences temperature changes I.E.: becoming wet from sitting in water, then you are probably getting water in the fuel. The fuel will condense when it sees pressure/temperature changes. The fuel will “quench” and produce water. Hope this helps
Ahhhh I see. Thanks Zach!
Sounds like its getting to much fuel Flooding.
Possibly!
Your choke cable isn't in place properly.
Okay! Thank you. Let me UA-cam some videos on choke cables.
I am no help but I'm sorry that happened! :(
Thanks! LOL