Brand new 703 control and brand new Yamaha T25 with electric start

[Solanilla]

I purchased a brand new Yamaha high torque T25 for my sailboat, along with a 703 control from Amazon. I can’t get the engine started, check the 10 pin connector and it seems to connect. There is no sound, no clicks, nothing
the electric trim tab works with my battery, so the engine is getting electricity.
there is the option to rope start the engine but I do not see any kills button in the engine other than at the 703 control

ibuave a multimeter and maybe I need to check but not sure what each pin does. Do anybody has an schematic of the 10 pin 70e control?

[99yam40]

what are you calling an electric trim tab?

do you have a key switch with the 703 that you are trying to start the motor with?

was this motor a remote-control motor before you installed this 703?

[yamaha1988]

It sounds like you’re facing an electrical connection issue, and you’ve already done a good job narrowing it down by confirming the trim works and the battery is supplying power. Here are some things you might want to check:

First, make sure the 703 control is properly grounded. A poor or missing ground connection can prevent the engine from starting while still allowing other functions like the trim to work. Double-check the ground wire at the control box and the engine.

The neutral safety switch inside the 703 control is another possible culprit. If the control isn’t in neutral or if the switch isn’t functioning correctly, it will prevent the engine from starting. Try shifting the throttle lever slightly forward and back while turning the key to see if it engages.

Since you have a multimeter, it’s a great idea to test the 10-pin connector. You can find Yamaha wiring diagrams online, but as a quick guide:

• The red wire is typically the 12V positive feed.
• The black wire is the ground.
• The yellow wire should carry ignition power when the key is in the ON position.

Check for continuity and make sure the red wire is supplying power to the control box. If you don’t have a schematic handy, there are a few forums and Yamaha resources where you might find one.

Lastly, ensure the kill switch on the 703 control is engaged. Even if it appears fine, try inserting and removing the lanyard to reset it.

Let us know how it goes! It sounds like a small electrical issue that should be solvable with a bit of troubleshooting. If you get stuck, I’d recommend reaching out to Yamaha support—they usually have schematics available for their controls.

[BQUICK]

Is that 703 control a Yamaha one or chinese repo?

[Solanilla]

Thanks to all advice.
it turned out the middle pin from the engine came pushed in so it did not connect. Took a needle nose plier and carefully pull it up and did the job.
my next “fix” is to see how to adjust the travel of the handle on the 703 has it engages FWD a bit violent, it goes away when I pull it back to the center. Will check if I have the required 11 mm set in the adjusting nut. I don’t have this issue going reverse. Maybe since it is a HT engine and propeller, the initial bite in the water looks violent.

i will go tomorrow to the mooring and do a double check.

[Solanilla]

One more thing. I would like to add a RPM gage and if possible a counter for engine hours or approximate. I went to the Yamaha website and not sure if they made one for a 25 HP. I see the extra cables on the 703 and I wonder if there is a way to connect an analog or digital rpm gage to it. Since sailboats are displacement vessels and never plane, having rpm data will help me with fuel management. The other engine hour counter is more from a maintenance perspective as the boat is in the tropics and is in the salt water environment all the time and there is no off seasons

[boscoe99]

What T25 model? They are not all the same.