omc shift interrupter system

[Chased2]

In what year did omc impliment the [h=1]omc shift interrupter system in their design. I have a 1987 omc 3.0 and im upgrading ignition. And troubleshooting my engine. If it has it where and what would it look like? Thx[/h]

 

[Lou C]

The original design had 2 switches and an ESA module. One is an interrupt switch that lowers the idle while shifting from in gear to neutral. The other is the overstroke switch which cancels the interrupt switch when you shift into gear. This would prevent the boat from being unable to run above idle if the interrupt switch stuck on. In later production they eliminated the overstroke switch and revised the ESA to incorporate a timer so that it would only lower the idle for a few seconds.
If you are looking to get rid of points ignition be aware you will have to upgrade the ESA module to one that works with electronic ignition or else your ESA won’t work. The ESA must function for you to be able to safely use the boat. On mine I kept the points...

 

[KM7]

Just FYI, I have a 91 Ford 5.8 L with the Prestolite breakerless ignition, (No points) It has both the Interrupter and overstroke switches.

 

[Chased2]

Thx for the input. I did locate the interruptor. It's on a w like cam. I have to put a couple diodes and resistors in to make it operate correctly.

 

[Scott Danforth]

Thx for the input. I did locate the interruptor. It's on a w like cam. I have to put a couple diodes and resistors in to make it operate correctly.

then you missed something. you should not need diodes and resistors to make it work with electronic ignition or with points.

shift interrupt was standard for many decades and goes back prior the cobra drive to the stringer drives and its on outboards too

 

[Lou C]

If what you have is the original ESA module that was designed for points and then added an electronic ignition system, (original poster) then yes there is an add on fix that is needed with diodes to make the shift interrupt work. Later models that had electronic ignition standard came with an updated ESA to work with it.