Motor won't stop!

[ppinny]

Hi there,
First timer, so please be kind;-))

Yamaha 60 hp four stroke high thrust motor, 703 remote control unit. No dials or other peripherals, just the basics installed.

After a prolonged period pulling a piece of string to get the motor started i eventually fixed the starter motor...... now i can't stop the engine!

The safety cut-off was broken but it used to stop on the key. Then it would stop sometimes on the key and usually after a minute or two if the key was left in the "off" position. Now it won't stop at all, unless i disconnect the fuel line. (Still takes ages....a tribute to how little fuel the motor uses i suppose!)

The main switch seems to be functioning OK and i have tested the continuity if the relevant wires back to the big multi-pin connector mounted on the front of the motor. That all seems OK as well.

It seems the main switch and the safety cutoff "make" a connection rather than break a connection to stop the motor so i assume the circuit fires a relay on the motor to do whatever it does. I've gone as far as i feel comfortable with but now i really need someone who knows how it works
so i can track down the problem.

Of course i may well be way off course already!

Thanks for you time reading this. I've tried to give a complete picture of where i've got to.

Ppinny, Panama

[boats.net]

Either bad key switch or a broken white wire or black wire in 10 pin harness or possible a bad CDI unit.

[99yam40]

Not positive on your motor but on most of the outboards I think the key & kill switch ground the circuit to kill the motor

[ppinny]

Hi boats.net,

If the key switch was broken wouldn't the engine stop switch still stop the motor?

The wires are good as far back as the multi pin on on the front of the motor. After that they disappear too deep for my level of confidence to disassemble!

Is the CDI unit the square, rubber mounted, 6x6x3/4 inch (ish) box on the front, behind the multi pin? It looks expensive! How can i check it?(The local repair shop wants $600 for a new 703 remote control unit! They also wanted to replace the starter motor which I have since taken to bits, cleaned, adjusted the brushes and put back together. It now works fine!) It was around $900, they said, for a new one.

Can i stop the motor by any other means until i get this sorted out? Or do i have to run it out of gas? Takes forever!

Did you see 99yam40's comment?

To you both.... i can't remember whether the black or white wire is the hot wire but if the main switch ( engine stop as well, obviously) has current then the fault might be deeper in the loom on the ground wire. Should i try connecting the hot wire from the main switch directly to the - battery terminal. Wouldn't that just mean that the off position on the main switch an/or the engine stop switch key removal would short and drain the battery!
So does this circuit trigger a relay that grounds the hot wire, but only briefly?
Thanks a lot for the help, Paul

My main issue right now is how to stop the engine.

[99yam40]

I did not mean it grounds the 12V power, it should ground the output of the CDI so that no voltage gets to coils