No Tach 2002 Vmax 225 OX66

[MartinLund]

Hello, i have searched far and wide for a solution but so far i am stumped.

I recently bought a 2002 225 ox66 engine that works great and is carefully maintanced. Everything works well except the tachometer.

I have tried two different tachs, 1 almost bran new livorsi mega series tach, and the digital multi tach that i got with the engine. There is no movement whatsoever on either tach. I have traced the wires and meassured continuity and no problems here. But when i meassure between ground and the green tach signal wire i get 0V.

I have also tried changing the CDI with no luck.

Is there anywhere else i can get the tach signal on this engine or any good troubleshooting tips ?

I have the engine on a self built catamaran and i really want the tach to be fully functioning before i test the boat so i dont overload the engine or anything.

[boscoe99]

Hello, i have searched far and wide for a solution but so far i am stumped.

I recently bought a 2002 225 ox66 engine that works great and is carefully maintanced. Everything works well except the tachometer.

I have tried two different tachs, 1 almost bran new livorsi mega series tach, and the digital multi tach that i got with the engine. There is no movement whatsoever on either tach. I have traced the wires and meassured continuity and no problems here. But when i meassure between ground and the green tach signal wire i get 0V.

I have also tried changing the CDI with no luck.

Is there anywhere else i can get the tach signal on this engine or any good troubleshooting tips ?

I have the engine on a self built catamaran and i really want the tach to be fully functioning before i test the boat so i dont overload the engine or anything.

The tachometer signal comes from the CDI. Have you measured the actual output from the CDI's to verify that it is present? If there is none you have two defective CDI's. Highly unlikely but not impossible

If either CDI has the tachometer signal then there is a wiring issue between the CDI and the tachometer.

The tachometer signal is conveyed via a green wire. First in the engine harness to the engine harness ten pin connector. Then in the ten pin harness itself from the motor to the key switch. Then in the mini-fused harness from the key switch to the tachometer.

[MartinLund]

Thank you for the answer!

Yes i have meassured the output directly from the CDI, i have used ac and dc between signal/green and ground. No voltage there.

The seller is shipping us yet another CDI but i have a hard time understanding that both are defect :/

I tried to connect the livorsi tach almost inn the engine so i know the cables are fine.

Is it possible to get the tach signal from the stator like i do on my merc 150 EFI or is it only possible to get from the CDI ?

Thanks in advance

[boscoe99]

I have run a Yamaha tachometer using a standard 120 AC volt to 12 DC volt wall wart. Transformer that is.

If you are familiar with how it works it first steps the AC voltage down from 120 volts AC to 12 volts AC. Then it converts the 12 volts AC to 12 volts DC via diodes.

The tachometer power and ground leads were connected to the 12 volts DC output but the tachometer signal lead was connected to the 12 volts AC. So what I am surmising is that I see no reason why you could not tap into the lighting coil and connect that to the tachometer signal lead.

[cpostis]

Hello, i have searched far and wide for a solution but so far i am stumped.

I recently bought a 2002 225 ox66 engine that works great and is carefully maintanced. Everything works well except the tachometer.

I have tried two different tachs, 1 almost bran new livorsi mega series tach, and the digital multi tach that i got with the engine. There is no movement whatsoever on either tach. I have traced the wires and meassured continuity and no problems here. But when i meassure between ground and the green tach signal wire i get 0V.

I have also tried changing the CDI with no luck.

Is there anywhere else i can get the tach signal on this engine or any good troubleshooting tips ?

I have the engine on a self built catamaran and i really want the tach to be fully functioning before i test the boat so i dont overload the engine or anything.

This post may help while you are trying to resolve your issues.

http://www.yamahaoutboardparts.com/f...r-th26988.html

[MortenLund87]

Origin of tachometer signal?

Hi!

Does anyone know where the ECU gets the original signal used to generate the tacho pulses?

Is this picked up from the pulser coils?
Could the crank position sensor be used for this? This is measured OK as far as we could understand!

We have tried 3 different CDI units now with no more success..

We also tried hooking the tacho directly to the stator output on one of the the green wires from the stator, but the tacho did not go over 1000 rpm and was very unstable. Thought this was the way the tacho was outputted on the old yamaha`s without CDI tacho output?

Hope someone has some "inside" information about the function of this ECU/CDI.. So little information about this units.....

Thank you,
Morten Lund