How to hook up tach on '98 Mariner 50hp 4 stroke?

[Zerex]

I just bought an older fishing boat with the above mentioned motor and I need to know how to hook up a tach to it.<br />The only idea I have is to somehow use the 1 and only plug that comes out of the controls but it has 6 wires to it.<br />The following are the colours of wires to the plug:<br />Purple <br />Tan<br />Blk<br />Grey<br />Tan with light blue stripe<br />Dark Brown with white stripe<br />Does anyone have a manual for this motor or know the colour combo that goes to the tach?<br />Thanc

 

[Dunaruna]

Re: How to hook up tach on '98 Mariner 50hp 4 stroke?

These are the only three you need for the tach - <br />Purple is 12v ignition.<br />Black is ground.<br />Grey is tach signal (sender).<br /><br />The rest are - <br />Tan - temp warning horn <br />Tan/white - temp gauge<br />Brown/white - trim gauge sender

 

[Zerex]

Re: How to hook up tach on '98 Mariner 50hp 4 stroke?

Thanx for the info

 

[Zerex]

Re: How to hook up tach on '98 Mariner 50hp 4 stroke?

Now this sounds stupid but can I use a car tach on this 4 stroke OB. The reason I ask is cause I hooked up an old car tach which u could set for 4,6,8 cylinders and with it set at 4 it said it idled at 3000rpm and when I went the other way to 8 it still said it idled at 2000rpm which doest seem right.<br />ANy ideas?

 

[Dunaruna]

Re: How to hook up tach on '98 Mariner 50hp 4 stroke?

You have answered your own question. <br />No, a car tach will not work. You need a marine tach, set the switch on the back to '6P'.

 

[Zerex]

Re: How to hook up tach on '98 Mariner 50hp 4 stroke?

Thanx again