Tohatsu 6 4 stroke, turning off at lower rpm

[athlon64]

So i have a 6hp 4 stroke tohatsu, about 6-7 years old. It has not been used this winter, now we have put it on the boat again and turned it on. It seemed to run well but as soon as you let the gas below about 30% engine engine starts do loose rpm and die. We took a ride and drove it at full speed for 10 minutes, it was running perfectly smooth at high rpm, you let the gas at about 30% witch is still not that low and the engines starts to loose power/dies.

What should i check?

Also can someone link me a good tutorial that will show me how to change the impeller on that outboard?

 

[pvanv]

Re: Tohatsu 6 4 stroke, turning off at lower rpm

Could be a lot of things, but fuel system is likely in 90% of these cases. Do you always, religiously, run the carb out at the end of each and every day? If not, you likely need a thorough carb cleaning. In fact, at 7 years, you may need one anyway. If the motor was stored with the carb "wet", that increases the odds of needing a cleaning by about 10 times.

The procedure for the cleaning is to remove the carb, completely disassemble it (including jets and emulsion tube nozzle, etc.), soak all non-rubber parts in real carb dip for 4 hours, and then blow everything out with a liberal and aggressive spray of generic carb cleaner, then reassemble, paying close attention to float height, then reinstall, and adjust the idle stop screw if needed.

Don't change just the impeller. Do a complete water pump kit. Lasts longer, and pumps better. The procedure is in the Factory service manual, available from any dealer, including many forum members, even me. Be sure to get a real Tohatsu manual, not an aftermarket manual. There are a number of videos on the web about that work.

 

[athlon64]

Re: Tohatsu 6 4 stroke, turning off at lower rpm

Could be a lot of things, but fuel system is likely in 90% of these cases. Do you always, religiously, run the carb out at the end of each and every day? If not, you likely need a thorough carb cleaning. In fact, at 7 years, you may need one anyway. If the motor was stored with the carb "wet", that increases the odds of needing a cleaning by about 10 times.

The procedure for the cleaning is to remove the carb, completely disassemble it (including jets and emulsion tube nozzle, etc.), soak all non-rubber parts in real carb dip for 4 hours, and then blow everything out with a liberal and aggressive spray of generic carb cleaner, then reassemble, paying close attention to float height, then reinstall, and adjust the idle stop screw if needed.

Don't change just the impeller. Do a complete water pump kit. Lasts longer, and pumps better. The procedure is in the Factory service manual, available from any dealer, including many forum members, even me. Be sure to get a real Tohatsu manual, not an aftermarket manual. There are a number of videos on the web about that work.

Well my father did clean the carburator once but that was years ago. So you think we should repeat that?

What do you mean entire water pump kit? What are its parts and how much does a new one cost?

 

[pvanv]

Re: Tohatsu 6 4 stroke, turning off at lower rpm

Yes, Do the carb first. In the future, be sure to always run the carb out at the end of each and every day.

WATER PUMP KIT : 4HP ~ 6HP
Description: Water pump repair kit. Includes all parts needed to service water pump. (cup, plate, impeller, bolts, drive pin, gaskets).
Fits: 5B 2-stroke model, 4/5/6hp 4-stroke models
Part # 369873221M, $46.59 Note: this is not the actual pic of your exact kit; yours is very similar.



Available from any dealer, including many forum members... even me