Ignition Sensor

[Bayou Dave]

The photo is like the ignition sensor in my 1987 Mercruiser 4.3L 175 HP, serial number 0B729840.
The one I found on iboats is the link here:

Ignition Sensor for Mercruiser 87-861780A2 87-861780Q4, GLM 73110 - Sierra 18-5116-1 - iboats

They don't look the same but the new one seems to be the only design that is available. I followed these part numbers 87-892150K02, 87-861780A-4, 87-861780Q-4 and ended up with the Sierra 18-511-1.

Do you think the new part will work?

 

[Don S]

Re: Ignition Sensor

Yes,

 

[Bayou Dave]

Re: Ignition Sensor

Thanks Don....

 

[achris]

Re: Ignition Sensor

The photo is like the ignition sensor in my 1987 Mercruiser 4.3L 175 HP, serial number 0B729840.
The one I found on iboats is the link here:

They don't look the same but the new one seems to be the only design that is available. I followed these part numbers 87-892150K02, 87-861780A-4, 87-861780Q-4 and ended up with the Sierra 18-511-1.

Do you think the new part will work?

The design with nuts and posts is the older design (same as yours). The new design has flying leads. The OEM kit comes with adapters to put the new design on the old system.

Chris....

 

[Bayou Dave]

Re: Ignition Sensor

I got the new sensor today and I am lost as to how to attach the wires. The old one has posts that come out the side of the distributor and the red/white and green/white wires attach to the posts. The new one has no posts to attach the wires, just the wires themselves coming through the side of the distributor. The new one also came with 2 short screws, that I see no place to use them. The new longer screws hold down the sensor, shorter one on starboard and the longer one on port where the existing ground wire attaches.
What am I missing?

 

[Don S]

Re: Ignition Sensor

Using the picture below, hook A to B, then hook C to D. Use the small screws and nuts to attach the ring terminal of A and C to the ring terminals of the wires that came off the old sensor.

Then tape them up or put some heat shrink over the small screws to insulate and isolate the screws from contact with anything else.

 

[Bayou Dave]

Re: Ignition Sensor

Now I understand what the shrink wrap that came with the new one is for. Thanks for solving the problem.

 

[Bayou Dave]

Re: Ignition Sensor

Don, I followed your directions, put it all back together and it fired right up! Time to finally get it in the water. Thanks...

 

[Don S]

Re: Ignition Sensor

Don't forget to check your timing. Shouldn't change, but you never know.