Tohatsu 40 hp starting issue

[Spotfin]

Hello iboats forum,

New to this forum, and need some help with my Tohatsu outboard.
I purchased the boat and motor this spring, both used. The outboard is a model MFS40A, and is a 2014 or 2015 model year.

I have a minor issue when starting it; not sure if it's just a quirk with the motor or something else. On a cold start, the motor starts right up everytime- turn the key to the run position and the motor beeps, turn to start and it fires right up. When I attempt to start it again (typically after I run it a bit and stop to fish) it does not beep when the key is in the run position and fails to start when I turn the key to start position. Turning the key to start a second time and the motor immediately fires up.

My local boat place (and Tohatsu dealer) is stumped. Other than the starting issue, the motor runs great and I'm happy with it. Is this just the way it is or is there something not working right?
Thank you.

 

[pvanv]

Sounds odd. What is your serial number? The MFS40A came out in 2014, and is still current production. When it fails, does it crank and just not fire, or is it dead?

 

[Spotfin]

Hi Paul,

the serial # is 052525AD.
After the motor is warm, it fails to start on the first attempt every time. It cranks and almost turns over.
I have two short video clips but it appears I can’t upload them.

 

[pvanv]

If you don't get the warning beep, it's possible the ECU is not initializing. I would check all wiring connections, especially grounds.If in doubt, clean them and reassemble. If you are getting the beep, there is a service bulletin related to that.

 

[pvanv]

View attachment 16-02.pdf

 

[Spotfin]

Thank you Paul! I will go through the wires this weekend.

 

[pvanv]

Based on your serial number, the tech bulletin applies; You or your dealer need to send the ECU to Tohatsu in Dallas. They will re-flash the programming, and return the ECU to you, along with 3 adapters that reverse the polarity to the ignition coils. After you reinstall the ECU and the adapters, the hot restart will be fixed.

 

[Spotfin]

Hi Paul,

Thank you again. What are your thoughts on this:
The boat has a Blue Sea Mini battery switch installed and only the motor is wired to it. Today I turned the battery switch to On and turned the motor key to the run position. The motor beeped and lights lit up. I then turned the motor key to the Off position without starting it, and to Run again. This time the lights did not come on and there was no beep( as it has done after running and trying to restart). To further experiment, I turned the battery switch to Off. I then heard a click noise in the motor. Switching the battery switch back to On, and motor key to Run resulted in the motor lights on and the beep. Could there be an issue with the battery switch? Thanks.

 

[pvanv]

Possible, but Blue Seas stuff is usually pretty good. I dunno what might click inside the motor, aside from the starter or PTT solenoids. If you heard a click when disconnecting power, something is very weird.

 

[Spotfin]

Does seem weird. Would it be worth connecting the motor wires directly to the battery, bypassing the switch, and see if the starting issue continues?

 

[pvanv]

Sure. But I expect the hot restart problem will need the ECU flash.

 

[Spotfin]

Update: I called Tohatsu and discussed the issue with my motor and your (Paul) recommendation. Ended up the tech I spoke to said he would call my local boat/Tohatsu dealer and request that they send the ECU back as they hadn’t been able to diagnose the problem. I picked up my boat this past Friday and tested it. It now starts like it is supposed to. Many thanks again for your advice!

 

[pvanv]

I take it they re-flashed the ECU?

 

[Spotfin]

Yes, they re-flashed it.