1986 4.3 OMC Cobra

[scottadams653]

Hey everyone, I am very new to this but I do have a couple questions. One is that when trying to put my boat in Forward it boggs down the engine and eventually dies. When putting the boat in reverse it works great. I cant figure out what is going on with it. It is going into gear perfict but its just very sluggish and wont speed up just dies. Any help would be great thanks again.

 

[cr2k]

Re: 1986 4.3 OMC Cobra

A little help on your part would be great. What are we working on? 4 cyl, v6, v8? What year What drive?

I have a flat tire, what size should I buy?

 

[Stanp1]

Re: 1986 4.3 OMC Cobra

1st guess is the interupter switch getting stuck. Look where your shift cable mounts on the top of the engine. there is a triangular thing-a-ma-gig that flips up and down. In the the middle of the thing-a -ma-gig is thin metal strip with a roller on it. When you shift into forward, the thing-a-ma-gig flips up, and pushes the thin metal rod with the roller causing the interupter switch to "interupt" the voltage on the coil and slow down the RPM's enough to let the outdrive go into gear. Once the drive is in gear, that Thing-a-ma-gig is supossed to flip down and dissengage the interuptor switch. if it doesn't flip down, your interupter switch is still engaged.

 

[a70eliminator]

Re: 1986 4.3 OMC Cobra

Stanp1 that's the best description I've read yet on the infamous Cobra shift interrupt/shift cable malfunction and I second that diagnosis of the stalling in forward gear dilemma.
The thing-a-ma-jig (lever) is spring loaded and should easily center itself, just move it by hand and see if it springs back in either direction for starters, make note of the little roller on the micro-switch it should land directly in the center of v notch

 

[bruceb58]

Re: 1986 4.3 OMC Cobra

To see if its the ESA is causing the problem just unplug the ESA and see if you still have the problem. You just have to realize that it may be close to impossible to shift out of gear so be prepared to turn of the motor to get it out of gear while you have it unpluuged.

 

[scottadams653]

Re: 1986 4.3 OMC Cobra

I unplugged the ESA and it ran fine just a little rough going into gear. I ordered one on ebay and it should be here thursday thanks everyone for all of the help.

 

[bruceb58]

Re: 1986 4.3 OMC Cobra

The problem is not the ESA but what is controlling it. Unplugging it just points you in the right direction.

As others have said, you need to see if its being engaged at the wrong time. The most common cause is a failing lower shift cable. When the lower shift cable fails, extra force is required to shift the drive which in turn cause the interrutp switch to enagage and turn on the ESA. The ESA should only be working coming out of gear.