OMC hard shifting....

[JustJason]

This has been done a million times before I know, but I've searched the archives and can't come up with a schematic or TS chart. Anybody have one?

1990 OMC 4.3 cobra with a clutch dog...

Goes into gear with 2 fingers...
doesn't want to come back into neutral easily...
engine idle is 575 in gear
the 2 microswitches work, i metered them out, they have continuity when pressed at almost 0 resistance (like .2 ohms or something)
but the esa is not cutting the engine, even if i press the switches by hand.
all of the wiring inbetween the esa and the switches and coil "appear" to be connected and in reasonably good condition. The weatherproof connecters were super clean on the inside and there's really no wire rot in the back of the boat.

Also... anyone know for a fact if i can just take out the esa and hotwire the switches to make it work like a merc? (i'm a poet and I didn't even know it) hehe.... thanks Don.

 

[Don S]

Re: OMC hard shifting....

Also... anyone know for a fact if i can just take out the esa and hotwire the switches to make it work like a merc

Yes, it can, but you wouldn't want it idling that slow. 650 to 700 and it will work.
I posted a drawing on what to do, let me see if I still have somewhere.

 

[Don S]

Re: OMC hard shifting....

 

[JustJason]

Re: OMC hard shifting....

If i'm reading that correctly, On the left hand side,
A. goes to ground
B and C are jumped together
D to coil neg

and then on the right side
D and C are left alone
B and A are cut and capped

And then I need to bring the idle up, is that right?
If it is, and just curious, what's the point of grounding A on the left side of the pic?

 

[fletcher0780]

Re: OMC hard shifting....

will that fix work with a pertronix ignition?

 

[JustJason]

Re: OMC hard shifting....

Ahhhh.... just took me a second and for me to draw it out myself on paper to get it.....
Now.... aside from just making the system that much more difficult.... why did omc use that esa module instead of just doing it that way/merc way?

 

[Boatin Bob]

Re: OMC hard shifting....

If everything is working fine there is less chance of stalling the engine with the ESA than with just the switch.

 

[JustJason]

Re: OMC hard shifting....

so then what's the point of the esa.... what exactly is it? When i went to boat school we didn't do omc..... (go figure). It cuts out the ignition with an input signal from the microswitches, but what does it do on top of that that the switches can't handle?

 

[Boatin Bob]

Re: OMC hard shifting....

On a Merc, the switch grounds out the coil for as long as the switch is made so if it's sticky or you shift really slow there is a good chance you'll stall the engine. With the ESA the electronic module pulses the coil so it's like only half the spark plugs get to fire. The result is the same, the engine RPM's drop which take the load off the gears and make it easier to shift out of gear back into neutral with less chance of stalling the engine.

 

[JustJason]

Re: OMC hard shifting....

ahhhh.... ok. Thanks for your help Boatin Bob and Don, much appreciated!!

 

[bruceb58]

Re: OMC hard shifting....

Why not just do it the right way and buy a new ESA. The newer ESA's don't need the overstroke switch either.

Also, if the points have been replaced by electronic ignition, the ESA won't function properly.

 

[JustJason]

Re: OMC hard shifting....

Don, Bondo, rodbolt.... anyone have an opinion of what works better/more reliably? Replacing or rewiring?

 

[JustJason]

Re: OMC hard shifting.... bump...

Re: OMC hard shifting.... bump...

bump

 

[Don S]

Re: OMC hard shifting....

Don, Bondo, rodbolt.... anyone have an opinion of what works better/more reliably? Replacing or rewiring?

Never really compared them. And they were done years apart.
For a customer, stick with OEM. Keeps you out of trouble when you try to engineer something to work ............ and it doesn't for the customer.

 

[danond]

Re: OMC hard shifting....

I have a Pertronix-equipped (with the ESA fix) 1989 4.3 and it shifts flawlessly using the factory ESA. All I get is a little "bump" going in and no noise or additional effort coming out. I don't take all day shifting, either. Quick and decisive into and out of gear and things work awesome.

Do it the way OMC intended and it'll work fine. Replacing the ESA is your simplest route to a solution, really. $60 and you're back in business.

 

[JustJason]

Re: OMC hard shifting....

For a customer, stick with OEM.

funny... i responded to a post the other day about a guy asking to jbweld his block.... i told him i'd never do it for a customer, but if it wasn't bad, sure it can be done....
I should just follow my own advice sometimes.... and yours.

 

[bruceb58]

Re: OMC hard shifting....

You know what else is funny...he will bring it to another mechanic someday and the mechanic is going to say that he needs an ESA but someone rewired it to work a different way. Customer is going to say "Well, that's the way i found it...". You know the rest of the story!

 

[JustJason]

Re: OMC hard shifting....

[copy=bruceb58]You know what else is funny...he will bring it to another mechanic someday and the mechanic is going to say that he needs an ESA but someone rewired it to work a different way. Customer is going to say "Well, that's the way i found it...". You know the rest of the story![/quote]

I know the end of that story all to often... its going to get a new esa... and that's it. Thanks everybody!!