OMC Cobra Shift assist inconsistent

[jtomanelli]

Hi fellow boaters!

I have an OMC 5.0 Cobra I/O in my 1988 Bayliner and replaced the point ignition system with a Pertronix one last year (By the way, recommend this to anyone)

I made the alteration to the ESA module wiring as posted on the Pertronix site and it seems to work... most of the time that is... it sometimes does not work and makes it difficult to shift out of gear.
I've tried to simulate the issue by tripping the micro-switches by hand and it seems to lower the revs as expected.

Is the ESA suspect or should I be looking elsewhere?

JT

 

[Mystic Dragon]

Re: OMC Cobra Shift assist inconsistent

I would check the actuation of the micro switches while in the water under load condition. It may be that the switch is not enguaging (only one is for the ESA, the othe is for over rev and shouldn't effect the shifting).

It may also be that the ESA switch is not consistant and needs to be replaced. These are the things I would check first. Other than that, if the engine does not lower RPM when shifting, it may be the ESA module, but as it is electronic, I doubt it would be intermittant unless the values of the components changed drastically and the signal is not differentiated corectly. Regardless, ESA modules are expensive and, if it turns out that you are ready to try this approach, I would recommend finding a used parts outlet rather than a new one. It just depends on how much money you watn to throw at it. Used ones don't wear out like mechanical parts. They generally work or don't work.

Good luck with it. I am hoping to do final adjustments on mine this Thursday and it is actuall an OMC ESA on a 2.5L Mercruiser. Initial tests show that it works, but I won't know until I get it in the water and put the prop under load.

Good luck!

 

[Mystic Dragon]

Re: OMC Cobra Shift assist inconsistent

One other thing. If this works sometimes then check all of your electrical connections first. You may have a terminal that is not making proper connection or just a loose wire.

 

[bruceb58]

Re: OMC Cobra Shift assist inconsistent

You need to determine if you have a mechanical issue or an electrical issue. Have some one shift the boat while you look at the linkage. Could be you just have an adjustment problem.

Do you have this problem in both forward and reverse? Do you have the newer ESA that does not use the overstroke switch?

 

[whywhyzed]

Re: OMC Cobra Shift assist inconsistent

Just buy the Rapair Pertronix compatible ESA, you can throw all the modification stuff away... the rapair ESA is only like $80 or something....your 20 year old OMC ESA is probably about to die anyways...that's all they last vibrating away on the engine there.....

 

[jtomanelli]

Re: OMC Cobra Shift assist inconsistent

Guys, thanks for info.

Mystic Dragon - I made the modification to mine as a result of changing out to the electronic ignition. I was told recently that this "fix" doesn't always work the best.

Just a note though, it does seem to work consistently when I manually trip the microswitch.

Bruce - I think you may be on to something... seems to do it when I shift out of reverse... in fact it sometimes stays stuck in reverse even under cable tension when I am trying to dock it. Do you suggest just re-adjusting the cable so it doesn't favor 1 direction over the other? I have the older ESA with the modification suggested by pertronix

KJD - if I find this to be the issue, I will dump it for the new one, but if adjustment is the issue a new part will not solve it.

 

[Boatin Bob]

Re: OMC Cobra Shift assist inconsistent

If you are going to try an adjust the cable have a read through Stuart Hasting's webpage first as he has described it very well
Stuarts OMC Page

 

[bruceb58]

Re: OMC Cobra Shift assist inconsistent

Not sure how much experience you have with how the lower cable works in this drive. At the drive end, it connects to a bellcrank in a small cavity. If you use your boat in saltwater, this cavity can get full of deposits so it can be harder to push in one direction over the other.

The other problem could be the shift cable itself. I went through many lower cables while I owned my Cobra. If you have to start doing adjustment on you lower cable, all of a sudden, it is a sign that the cable is failing.

One thing that I did do was to change out the bellcrank shift bushing to the newer version that has a grease fitting on it so that you can fill the bellcrank cavity with grease.

 

[jtomanelli]

Re: OMC Cobra Shift assist inconsistent

Bruce, the cable in question is not the lower cable (at least I don't think so). It is the one that leads to the engine and trips that switch during shifting. Although you may be on the money with the cable replacement.

I have never gone that deep into my lower unit and am a little scared to, to be honest. Can you recommend a good manual that shows some of these items blown apart?

 

[bruceb58]

Re: OMC Cobra Shift assist inconsistent

The pressure from the cable going to the drive is what causes the interrrupt to operate. That is why it only operates when it comes out of gear...because there is more pressure on the lower cable.

i would look for a factory OMC manual(ebay) along with an in depth look at Stuart Hasting's Cobra site referenced in a previous post.

 

[jtomanelli]

Re: OMC Cobra Shift assist inconsistent

Thanks again for all suggestions/recommendations!

I will invest in a good manual and start learning

 

[#1CATDADDY]

Re: OMC Cobra Shift assist inconsistent

Hi fellow boaters!

I have an OMC 5.0 Cobra I/O in my 1988 Bayliner and replaced the point ignition system with a Pertronix one last year (By the way, recommend this to anyone)

I made the alteration to the ESA module wiring as posted on the Pertronix site and it seems to work... most of the time that is... it sometimes does not work and makes it difficult to shift out of gear.
I've tried to simulate the issue by tripping the micro-switches by hand and it seems to lower the revs as expected.

Is the ESA suspect or should I be looking elsewhere?

Can you give me some info about the ESA module posting(E-SITE) and did you check the shift interruptor? I am having same issue.(1991 OMC 5.7L)

 

[Coors]

Re: OMC Cobra Shift assist inconsistent

Bruce, how to tell if you have the newer shift? where is the grease fitting?

 

[bruceb58]

Re: OMC Cobra Shift assist inconsistent

Coors,

I am not sure what you are asking about but since you mentioned "grease fitting" I will assume it is the updated bellcrank bushing. It would be parts 79 and 83 in the picture. The grease fitting would be at the outside of the bushing cap.