Rodbolt, Townsend, Boscoe--Tach/Harness

[Jason2tpa]

hey boys. My pops was cleaning out the garage today and found a box containing a yam tach and wiring harnesses. This tach was used on a mid 90s 2 stroke 150. No part number on the tach, it's pictured below.

The tach to ignition harness and engine to tach harnesses are brand new. I do not know the part number of the engine to tach harness, but it's pictured below. However, I do have a part number for the tach to ignition harness: 6Y5-83553-20

Here are my questions:

1. Can the tach pictured be used for my '98 S115TLRW?
2. Can the 6Y5-83553-20 harness be used with this engine and this tach?
3. Can the engine harness pictured be used with this engine and this tach?

My pops did mention that the backlight of this tach might be blown. Numbers show, just no light. However, he can't recall if its this tach or some other gauge he replaced. If this tach is good to use with my engine and determine that the backlight is blown, can this backlight be replaced?

Thanks guys.

[TownsendsFJR1300]

I don't have a clue, sorry...

I don't like electrons, too negative...

[Jason2tpa]

Do you know of a online source that would list yamaha gauges with corresponding part number? If I can locate the part number with picture of tach and just visually compare I can then determine if the tach can be used for my engine. Boy it'd be nice if the number was on the back of tach. That would be too easy tho.

[TownsendsFJR1300]

Do you know of a online source that would list yamaha gauges with corresponding part number? If I can locate the part number with picture of tach and just visually compare I can then determine if the tach can be used for my engine. Boy it'd be nice if the number was on the back of tach. That would be too easy tho.

This is the closest thing I have that may help:

2014 Yamaha MRP Catalog

Boscoe might have the part #(He has all the odd #'s, parts, etc in his secret files).


.

[boscoe99]

The tachometer appears to be a -80 or -81. It is compatible with the motor you have. That is also the correct harness for it.

Get a headlight lens restoration kit and you should be able to clean up the tachometer.

Backlight is not fixable per Yamaha.

[99yam40]

just have to not boat at night, or if you do carry a flashlight to see the gauge

[Jason2tpa]

The tachometer appears to be a -80 or -81. It is compatible with the motor you have. That is also the correct harness for it.

Get a headlight lens restoration kit and you should be able to clean up the tachometer.

Backlight is not fixable per Yamaha.

Thanks boscoe. I did hook up the tach and it functions. However, no numbers are visible when the backlight is on. Per the wiring diagram, when the yellow and blue wires in the middle of the harness are conmected the light comes on with ignition. When I disconnect the yellow and blue wires and turn on the ignition the tach numbers are visible. So, when backlight wiring connected--No readout. With backlight wiring disconnected--Readout.

Ideas on why?

[pstephens46]

The last thing you need running at night is the tach.