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Tohatsu 20 Hp went completely dead

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Billr982

New member
I took my boat out and got half way across the lake when the motor started to slow and then just quit. I went to restart the motor and it would not crank from the battery. I tried pull starting it ran for a few seconds and then quit. I got a tow back and pulled the boat out of the water. checked neutral swicth and emergency stop switch, both are working properly does anyone have any ideas as to what might be wrong.
 
What is your actual model? When you say it would not crank, did the starter engage at all? Is there fuel at the motor?
 
My motor is a 20 Hp 2010 mfsceptl The starter did not engage and there is fuel to the motor. When I got home I put a jumper on and the starter engaged and the quit again.
 
Was it overheating ( water intake blocked ) ?-----Water in the fuel ?------Perhaps test run with another tank and hose.----Get the battery load tested as well.
 
racerone said:
Was it overheating ( water intake blocked ) ?-----Water in the fuel ?------Perhaps test run with another tank and hose.----Get the battery load tested as well.
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Fuel was just fresh in the tank, tank was dry when filled. Water was flowing through cooling system at least it was pumping it out of the discharge. Had battery load tested just got home from that.
 
OK, so you have two distinct problems. One is electric start, and the other is stalling.

A number of things could cause the failure to electric start. You cannot start in gear, for example. Likewise, if the starter solenoid is not engaging, 12v will not go to the starter motor. If the 20a fuse is blown, the solenoid will not engage. If you are properly grounded, and you apply 12v to the starter, it should turn. If not, there may be an issue in the starter motor.

For the motor to slow down and stop, that is usually fuel starvation. If you have a bad o-ring in the primer hose (or it's not seated correctly), air can get drawn into the fuel system and cause stalling. So can a closed tank vent. When it stalls, you can open the drain on the side of the carb (uses an 8 mm socket) about a half turn and see if a few ounces of fuel comes out. If only a drop or two, the carb is dry.
 
pvanv said:
OK, so you have two distinct problems. One is electric start, and the other is stalling.

A number of things could cause the failure to electric start. You cannot start in gear, for example. Likewise, if the starter solenoid is not engaging, 12v will not go to the starter motor. If the 20a fuse is blown, the solenoid will not engage. If you are properly grounded, and you apply 12v to the starter, it should turn. If not, there may be an issue in the starter motor.

For the motor to slow down and stop, that is usually fuel starvation. If you have a bad o-ring in the primer hose (or it's not seated correctly), air can get drawn into the fuel system and cause stalling. So can a closed tank vent. When it stalls, you can open the drain on the side of the carb (uses an 8 mm socket) about a half turn and see if a few ounces of fuel comes out. If only a drop or two, the carb is dry.
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I checked the starter checked fuel flow, all of the symptoms started at the same time, everything was fine until the motor slowly came to a stop and everything just went dead no blown fuses checked all 4 of them checked neutral switch it is working properly. I tore everything down anf checked everything I could think of.
 
There is only one fuse.

So you still have two issues, probably unrelated. Diagnose the starter, and diagnose the stalling.

If this seems daunting, check with your local dealer for assistance.

Billr982 said:
I checked the starter checked fuel flow, all of the symptoms started at the same time, everything was fine until the motor slowly came to a stop and everything just went dead no blown fuses checked all 4 of them checked neutral switch it is working properly. I tore everything down anf checked everything I could think of.
Click to expand...
 
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