How to get tach signal from automotive distributor........

[Fordiesel69]

The previous owner removed the marine distributor from my 165HP six, and installed an all in one automotive one with the coil in the center. I noticed they twisted the two tan wires together and wired it to the B+ on the distributor, and the two dark brown wires together with nothing else.

Although I do not endorse this conversion, I am stuck with making it work to keep costs down and it actually runs nice with it. Now I just need a tach working....

Here is a pic you can click FULL SIZE to see the wires I am talking about. Same setup as my 165HP, but this is on a 120HP.
http://image55.webshots.com/855/2/58/85/2193258850044425697UJbnZf_fs.jpg

 

[ussoldier_1984]

Re: How to get tach signal from automotive distributor........

ehhh most of the guys here are gonna tell you your boat is not safe and will explode.

 

[Don S]

Re: How to get tach signal from automotive distributor........

The tach signal doesn't come from the distributor, it comes from the - terminal on the coil.

 

[Fordiesel69]

Re: How to get tach signal from automotive distributor........

I understand that part, GM placed a TACH terminal on the exterior of the distributor, so what I am asking is what wire(s) do I need to place on that ternimal?

This is how the old setup was:
Do both (-) wires just tie onto the TACH terminal?
http://image55.webshots.com/855/2/58...7UJbnZf_fs.jpg

 

[Don S]

Re: How to get tach signal from automotive distributor........

Why, you have a marine tach, just use the coil, no need to even mess with your automotive distributor, if you want to know about your automotive distributor, check with a chevy car forum, they probably know.

 

[RogersJetboat454]

Re: How to get tach signal from automotive distributor........

I understand that part, GM placed a TACH terminal on the exterior of the distributor, so what I am asking is what wire(s) do I need to place on that ternimal?

This is how the old setup was:
Do both (-) wires just tie onto the TACH terminal?
http://image55.webshots.com/855/2/58...7UJbnZf_fs.jpg

You should hook your tach wire up to one of these;
http://www.summitracing.com/parts/MAA-9-26309/

Replacing the distributor with a marine grade unit is $481.00 from Summit. Replacing lives lost by being cheap and using a 30+ year old HEI distributor never intended for confined use in a marine environment is $481.00 X ∞.

It's much cheaper to use a marine grade distributor.