petronix ignitions & coils for 1979 OMC stringer?

[bradrulz]

1st off, this forum is awesome, i'm learning so much reading through all the posts. Thanks, all.<br /><br />I'm running through the ignition system of my 1979 OMC 120HP stringer (4cyl), and i'm thinking about converting to electronic ignition. I hear Pertronix Ignitor is a good way to go to upgrade it, but I understand the need for extra resistors (following their online diagram at http://www.pertronix.com/tech_support/assets/diodefix.pdf). <br /><br />My question is should i be going this route while diagnosing the engine, or keep everything stock until i find out whether it's the ignition system, fuel system, both or something else keeping her down?<br /><br />Thanks for any advise, I realize this question is more of a philosophical one than a specific technical detailed one. Maybe i'll graduate to those soon enough. <br /><br />-brad

 

[Boomyal]

Re: petronix ignitions & coils for 1979 OMC stringer?

For some reason your url does not work. If it is refering to the mods necessary for a shift interupt, forget it, you don't have one. Your stringer uses a hydraulicaly assisted cable shift and does not have to shut the motor off to do such.<br /><br />IMHO,I'd go ahead and buy the set-up but diagnose your problem before you install it. Be sure to buy the Pertronnix II. It won't burn out if you leave your key on. Also be sure to save your points and condensor w/plate. Seal it in a ziplock and toss it in the glove box. You can always revert back to points if need be.

 

[bradrulz]

Re: petronix ignitions & coils for 1979 OMC stringer?

Thanks, Boomyal, i recognize your handle from many posts i've read. appreciate the advice.<br /><br />I like that i don't need to solder any radio shack resistors to anything. Here's the link to what Pertronix pointed me to:<br /> http://www.pertronix.com/tech_support/assets/diodefix.pdf <br /><br />When i talked to their tech support, he told me that i should get the Ignitor II and Flamethrower II coil, and then to eliminate all other resistors completely. Can't say i was 100% following him on that one, but i'd love to hear from you (all) before i go purchase their fleet of products for my motor.<br /><br />Good call, carry extra parts.

 

[Boomyal]

Re: petronix ignitions & coils for 1979 OMC stringer?

The "all other resistors", I believe, was refering to the ballast resistor for the coil. It reduces the voltage to the coil. It is something you do not want for the Pertronix. If you follow one of the positive leads back from the coil, it should terminate at a 'block' encased in metal mounted somewhere at the rear and top of the engine. That would be your ballast resistor. The other lead, to the positive coil terminal, would come from the starter solenoid. It is intended to give the coil a 'shot' of twelve volts while the starter is cranking. Otherwise it has no voltage to it.<br /><br />Disconnect the two leads on the ballast resistor and join them together. You can just leave the BR in place. It's great not to have to mess with points and you do get a better spark to the plugs.