OMC Electronic ignition conversion problem

[Chris Lifka]

Hi

I'm new to this so I don't know if this is the right place to post this but I sure could use some help.
I have 1990 Four Winns with a ford 302 and an 200 Cobra Outdrive. The previous owner changed out the regular points type ignition in 2006 with a Prestronic (not sure of the spelling) one. I also have the system with the shift interrupt.

The problem seems to be the alturnator keeps putting out to much voltage and it causes the engine to miss on 3 cyclinder. Not all the time but too often to enjoy the day. I have changed alturnators and thats no help. The boat runs perfect when the alturnator is off the boat.
I'm the owner and the mechanic working on it has does not know what to do.
He thinks maybe the person who installed the electronic ignition wired something wrong but we don't know how to our hands on the install instructions without buying and new ignition kit. He says he has heard some talk about putting some resistors in line but he is not sure how to do that.

I hope someone can help before I go broke while my mechanic keeps trying stuff that does not work.

Thanks

Chris

 

[Rocky_Road]

Re: OMC Electronic ignition conversion problem

Welcome aboard, Chris!

The unit you have is made by Pertronix Performance Products.

Here is a recent thread about this conversion:

http://forums.iboats.com/showthread.php?t=301661

The Pertronix website is:

http://www.pertronix.com/

You should use the search function on this forum, to find all the threads talking about Pertronix.

I'm sure that you will be getting a lot of help from the experts here!

 

[HT32BSX115]

Re: OMC Electronic ignition conversion problem

Howdy,

Try the following. http://www.hastings.org/~stuart/cobra/

There is some Pertronix info there.


Regards,


Rick

 

[Rocky_Road]

Re: OMC Electronic ignition conversion problem

Here are some OMC answers from the website. I see that this page includes the installation instructions....

http://www.picosearch.com/cgi-bin/ts.pl?index=439864&query=OMC&search=Search

 

[Chris Lifka]

Re: OMC Electronic ignition conversion problem

Thanks for the responses.

I think the conversion kit was made a company called Prestolite.
I went to the repair shop yesterday and the mechanic showed me the problem. When the boat was first started and a held high idle of 1k rpm the voltage guage started to climb, once it hit 15 volt the engine would shut down on number 3, 5 &7 cyclinders. If you brought the idle down to normal (800) and then the charging backed off and the engine resumed normal smooth idle . Also, if while it is breaking up you hit the trim button the engine will clear up because the amps are being used elsewhere.

Is there any wiring diagrams for the Prestolite kits? I called them and they discontinued making those kits and couldn't produce anything for me.

Is there a resistor I can put in line to reduce the voltage to the batteries because it seems the built in regulaor does not know to cut back the output of the alternator.

Thanks for your help

Chris

 

[Don S]

Re: OMC Electronic ignition conversion problem

Is there a resistor I can put in line to reduce the voltage to the batteries because it seems the built in regulaor does not know to cut back the output of the alternator.

Why don't you fix the problem, and not put a bandaid on the ignition system. Get the alternator checked out and fixed, also the battery load tested.
No sense fixing the ignition system with a faulty charging system.

 

[-C- IMP]

Re: OMC Electronic ignition conversion problem

If my memory serves me there is a wire that runs from the distributor to the alternator that is a resistance wire. Check your wiring diagram for color. I think this wire should be replaced with non-resistant wire.

 

[gdombroski]

Re: OMC Electronic ignition conversion problem

Is your coil getting hot to the touch? What's the voltage to the coil when running? If you have a owners manual it will have the wiring scematic. On mine I believe the resistance wire is purple/black. There should be two wires to the + side of coil one solid and the resistor. If you have 12volts to the coil when running (not during start) you will burn out the ESA.

 

[Howard Sterndrive]

Re: OMC Electronic ignition conversion problem

When the boat was first started and a held high idle of 1k rpm the voltage guage started to climb............... 15V

I'd say it's climbing because your alternator's voltage regulator is shot. 14.5V is max. it should ever climb to. Then the voltage regulator reduces the excitation to the field if it's functional.

 

[gdombroski]

Re: OMC Electronic ignition conversion problem

When the boat was first started and a held high idle of 1k rpm the voltage guage started to climb............... 15V

He's not saying the voltage at the coil is 15 it's the guage. I believe the excitor reduces the battery charge voltage to around 12V to the coil. My engines always charge at about 14.4v