70 BETO 6H3 model year?

[The_Lamia]

Hi,
my name is Marco and am living in Perth, Western Australia. New to this forum as I have just bought an old Pacemaker with a 70HP Yamaha.

The engine is running fine, but have couple of gauges not working (Hours and Trim) and a bunch of "spaghetti" coiled under the console.
In the effort to give back to this 80ies boat some dignity, I need to understand which year is the engine.

The nameplate says:
70 BETO 6H3 L 470517
Any idea which the model year?

Also I have what seems to be an old 703 control box. Anybody know where I can find a wiring diagram for it.

Cheers

Marco

[boscoe99]

Cheers mate. Where is that darn airplane? Is your last name Polo? I think I have heard of you.

Looks to be a 1989 model year motor.

Not shown in the diagram below are the wires that might be dangling from the control box and which are used for a remote trim switch. Yam usually drops the ball when it comes to data.

[The_Lamia]

Thanks for the quick info.

I think the plane is somewhere else, but is a big and rough ocean out here.


It seems it is a 1989 model, judging by the part drawings for the 70ETLF.


So the drawing you posted is the 703 box itself. It should exist a drawing showing the whole interconnecting between control box, motor and gauges somewhere. Am I right?
Have you ever seen something like that?

Cheers
Marco

[boscoe99]

I have

[boscoe99]

What type of gauges? Yam analog or digital display multi-function?

[The_Lamia]

Are the old analog versions.

The hour gauge is the mechanical one.

Cheers

Marco

[boscoe99]

[The_Lamia]

Almost there.

Over the week end have checked what I have on the boat with the last diagram you posted and is close.

My Trim Gauge 4 pole connector has four wires (black, orange, grey and pink) and not three black/red, orange/red and pink/red) as shown in the diagram, but it doesn't stress me too much as the fourth wire is present all the way to the trim sender with same colours.

From the Relay Unit beside the two connectors (going left and right on the diagram) instead of the two wires (yellow and black) in the centre, I have a third wire (pink) and the three of them are terminated into a multi pin connector coming off the main bundle (the one coming from the 703 box, in the diagram with the "single fuse" label) and the pink wire is connected to a white one.

So everything should be good, but the trim gauge doesn't move.
I read in some post a "...usually is the sender..." comment.
How to prove if the sender is working or not?
Is there a way to send some power and measure some output? What kind of signal should I measure? Or can I inject the meter with some signal to prove it is working?
Any help welcome.


I have also an analog mechanical hour meter that is not working because the wire were cut.
There are four of them: blu and black that are the light and yellow and black that are the "signal". It is ok to connect them to the yellow and black coming out the bundle that is connected to the 703 box?

Also mid way from the bundle from the 703 box there are a blu and a yellow that are said "TO LIGHT SWITCH". Is this light switch just a contact free of voltage or should I energise with 12v to turn on the meters light?

Thanks for the help.

Marco

[boscoe99]

Almost there.

Over the week end have checked what I have on the boat with the last diagram you posted and is close.

My Trim Gauge 4 pole connector has four wires (black, orange, grey and pink) and not three black/red, orange/red and pink/red) as shown in the diagram, but it doesn't stress me too much as the fourth wire is present all the way to the trim sender with same colours.

From the Relay Unit beside the two connectors (going left and right on the diagram) instead of the two wires (yellow and black) in the centre, I have a third wire (pink) and the three of them are terminated into a multi pin connector coming off the main bundle (the one coming from the 703 box, in the diagram with the "single fuse" label) and the pink wire is connected to a white one.

So everything should be good, but the trim gauge doesn't move.
I read in some post a "...usually is the sender..." comment.
How to prove if the sender is working or not? There should be a procedure in the service manual that specifies how to test the sender. Two wire senders I am familiar with. Four wire senders no.
Is there a way to send some power and measure some output? What kind of signal should I measure? Or can I inject the meter with some signal to prove it is working?
Any help welcome.


I have also an analog mechanical hour meter that is not working because the wire were cut.
There are four of them: blu and black that are the light and yellow and black that are the "signal". It is ok to connect them to the yellow and black coming out the bundle that is connected to the 703 box? Yes. Yellow is 12 volts positive. Black is the ground. When the key is in the ON position power will be provided to the hour meter and it will start recording engine time. Key on time actually so don't turn the key on and forget to start the motor.

Also mid way from the bundle from the 703 box there are a blu and a yellow that are said "TO LIGHT SWITCH". Is this light switch just a contact free of voltage or should I energise with 12v to turn on the meters light? If the blue wire and the yellow wire are connected together then any time the key is in the ON position the internal instrument lights will be illuminated. If a separate light switch is connected to the blue and yellow wires then the instrument lamps will only illuminate when the light switch is in the ON position and the key switch is in the ON position.

Thanks for the help.

Marco

See comments above.

[The_Lamia]

Do you know where to find a service manual for such engine?

Cheers

Marco

[99yam40]

your local Yamaha dealer should be able to get one for you or at least get the proper manual # and then look on the web for other places to find it

[The_Lamia]

I found the service manual.

It says to measure the resistance across the wires of the sander:
Pink-Black should read 360-540 Ohm
Black Orange should read 800-1200 Ohm.

My is on the range of the 3 kohm and the reading doesn't change much moving the sender lever.

I think it's gone and I need a new one.

The guy that gave me the pages of the service manual, gave me a used, but better than mine trim gauge. It is same graphic than mine, but with 3 wires instead of four.
My motor is 1987, this gauge is of a 1989 motor.

The sender of course is different. I've check on boat.net and the 3 wire sender is 6H1-83672-10-00 while the 4 wire is 6E5-83672-01-00.

Does anybody know if the screws template is the same or different for the two models?

If I buy the 3 wires, will it fit on my motor?

[boscoe99]

What makes you now say that your motor is a 1987 model?

[boscoe99]

Here is a diagram from a 1989 70 HP Yam SM. It shows a three wire sender. Unfortunately the diagram is for the multi-function gauge and not an analog gauge but the wiring from the motor to the dash should be the same.

[boscoe99]

Hi,
my name is Marco and am living in Perth, Western Australia. New to this forum as I have just bought an old Pacemaker with a 70HP Yamaha.

The nameplate says:
70 BETO 6H3 L 470517
Any idea which the model year?

Marco

Here is data from a Yamaha document that indicates engine serials from 468613 through 473104 are 1989 model year motors. Your serial is in the middle of this range.