Total Noob Motor Questions

[cheburashka]

Re: Total Noob Motor Questions

Thanks for the tips.
Is it possible that I now need to advance or retard the timing since I've added the electronic ignition?

There's part of your trouble.

The trigger mechanism that mounts to the rotor lobes doesn't match up exactly with the original position of the lobes. No way it can. Of course you'd have to reset the timing after installing the new system, just like you'd have to reset the timing after installing a new set of points. I'll bet your timing is waaaay off.

The other thing is related to what Fishermark wrote. Looking at your picture, I can't tell where you've attached the positive terminal of the ignition system. You need to bypass the ballast resistor wire and run power to the system in accordance with the instructions. Is it possible that it doesn't have 12V?

For the record, I run the same system in my boat and I'd never go back. I keep the points plate with condenser and points from the old system in the glovebox, just in case something goes wrong, but the boat runs a whole lot better with the Pertronix system than it did with points, and there's no need to check gap, dwell etc.

And I also filed a groove in the distributor cap, as the instructions advised.

 

[Shomare]

Re: Total Noob Motor Questions

The directions required that I attach the black wire to the negative coil terminal and the red wire to the positive coil terminal since I don't have a primary ballast resistor.

It is a 12v system.

I really appreciate all the help and trouble shooting.

Thank you all who have responded.

 

[Maclin]

Re: Total Noob Motor Questions

The coil may have ballast resistor wire in the circuit instead of a separate ballast resistor. The wire is several feet long and kind of lumped together somewhere in the harness if you have one. It is best to run the red wire to a known 12v source that is only on with the ignition. If you are positive there is no ballast resistor in the circuit at all and that the coil is designed to work without ballast then you can leave it as is.

 

[Maclin]

Re: Total Noob Motor Questions

I think that purple wire hooked to the coil is ballast resistor wire....cheburashka referenced this wire as well. Most if not all points type ignitions had ballast for the coil. I believe you have to connect the red wire to something else, it will not be at 12 volts like that.

FWIW.....My brother bought a boat that had the pertronix installed wrong like that, had very unreliable and weak spark, hard starting. We went back to points at the lake one weekend once we figured out it was wrong and he tossed the pertronix in the trash (his choice, we could have hooked it up correctly but he did not trust it by that time, he is way more comfortable with points, I am more the electronic type than he is). Admittedly most of his problems were from the prior owner's cobbling job more than from any perceived pertronix quality issues.

 

[Coors]

Re: Total Noob Motor Questions

Don't some coils have an internal resister? It should state, on the outside of the coil.

 

[Fishermark]

Re: Total Noob Motor Questions

To simplify things it is easiest to buy a coil from pertronix as well. At the very least make sure you have an internally resisited coil and as mentioned above, make sure you have a full 12v to the coil. An easy way would be to run a wire from the battery to the coil - then start the engine. If it runs you've identified the problem and can wire it up more permanently.

 

[Shomare]

Re: Total Noob Motor Questions

Thanks for the resister / coil info. I'll double check that after work tonight and I'll post some current photos of the set up.

 

[Shomare]

Re: Total Noob Motor Questions

o.k. Took a lot of photos of wiring, distributor, coil, and engine info.

The coil clearly says external resistor, but I traced the wires, and can't find anything that resembles a ballast resistor in the wiring.

 

[Shomare]

Re: Total Noob Motor Questions

 

[Maclin]

Re: Total Noob Motor Questions

The coil says to use with external resistor so we know it is not internally ballasted. There must be a resistor in the circuit somewhere or you could have coil saturation problems while it is running.

I think the purple wire connected to the coil positive terminal, the one in with the other wire with a stripe, is part of a longer resistor wire, but I might be wrong. Easy to check though if you have a voltmeter. Turn the ignition on (just on, not cranking) and measure voltage at the positive terminal on the coil, choose a good ground. If it is close to 12 volts then there is probably not a resistor in the circuit. If it is more like 9 or 10 volts then there is a resistor in the circuit whether it be a length of resistor wire folded up or a physical resistor component somewhere.

Either way I think you need to power the pertronix unit from another source. Here is why I think that...If there is no ballast resistance in the circuit you need to add it back in. Once you do that the pertronix will not be getting the correct voltage at the coil.

 

[Maclin]

Re: Total Noob Motor Questions

I retraced the steps I wen thru with my brother and found this, (Fishermark may remember this advice, I think it is in response to questions from him...!)



Quote from a Boatengine.net forum

"Hello, I have practically the same setup as you and I also have since converted it to electronic so I can speak from experience! Here goes!

Yes, you have a resistor in your ignition circuit. It is not the same resistor like the one in your car. It is a resistance wire. The resistance wire color is purple. It connects to the alternator output wire a little after the large cannon plug at the back of the engine. The alt output wire is also purple. You will see 12 vdc when the key is on and you probe this wire. The resistor wire is not a great setup. I had problems with mine changing voltages as the wire heated up. It drove me crazy because the engine would run great for about an hour and quit. The wire was changing resistance and letting the coil overheat. Then the motor would quit! You could change the resistor wire or just add a ballast resistor from auto supply. The Pertronix system is made to use the original coil and resistor setup. If you keep the stock coil you need to use some kind of resistor or you will overheat the coil. I would do this instead, Ditch the original coil and pick up a flame thrower coil from pertronix. Or get a 12 volt universal coil with brass terminals (so they don't rust) Find the purple wire where the resistor wire connects (remember they junction right near the cannon plug) and clip the resistance wire there. Tap that spot for switched 12 volts and hook up that to the positive side of the coil. Hook up your pertronix ignitor wires to pos and neg of the coil and install the ignitor in the distributor and you will be all set. No more resistance wire and fickle Mercruiser stock coil. The pertronix likes straight 12 volts as opposed to the 6 to 9 you will find at the end of a resistance wire. You will eliminate a bunch of Gremlins doing it this way! Good luck!"

 

[Shomare]

Re: Total Noob Motor Questions

Holy **** that a lot more involved than I though it was going to be. Not as advertised by Ignitor!

I'm going to have to call in one of my mechanic buddies and get an assist at this point.

 

[Coors]

Re: Total Noob Motor Questions

I retraced the steps I wen thru with my brother and found this, (Fishermark may remember this advice, I think it is in response to questions from him...!)



Quote from a Boatengine.net forum

"Hello, I have practically the same setup as you and I also have since converted it to electronic so I can speak from experience! Here goes!

Yes, you have a resistor in your ignition circuit. It is not the same resistor like the one in your car. It is a resistance wire. The resistance wire color is purple. It connects to the alternator output wire a little after the large cannon plug at the back of the engine. The alt output wire is also purple. You will see 12 vdc when the key is on and you probe this wire. The resistor wire is not a great setup. I had problems with mine changing voltages as the wire heated up. It drove me crazy because the engine would run great for about an hour and quit. The wire was changing resistance and letting the coil overheat. Then the motor would quit! You could change the resistor wire or just add a ballast resistor from auto supply. The Pertronix system is made to use the original coil and resistor setup. If you keep the stock coil you need to use some kind of resistor or you will overheat the coil. I would do this instead, Ditch the original coil and pick up a flame thrower coil from pertronix. Or get a 12 volt universal coil with brass terminals (so they don't rust) Find the purple wire where the resistor wire connects (remember they junction right near the cannon plug) and clip the resistance wire there. Tap that spot for switched 12 volts and hook up that to the positive side of the coil. Hook up your pertronix ignitor wires to pos and neg of the coil and install the ignitor in the distributor and you will be all set. No more resistance wire and fickle Mercruiser stock coil. The pertronix likes straight 12 volts as opposed to the 6 to 9 you will find at the end of a resistance wire. You will eliminate a bunch of Gremlins doing it this way! Good luck!"

Does not that state; use the resister coil, but don't?

 

[Don S]

Re: Total Noob Motor Questions

Here is the instructions FROM PERTRONIX for installing an ignitor system.
http://www.pertronix.com/support/manuals/pdf/ignitor12vneg.pdf
All Mercruiser 3.0L engines with points distributors have a resistor wire in the system.
Other than cutting slots in a distributor cap, it's a fairly easy installation if you follow the instructions, and really, I have NEVER seen that mentioned from Pertronix.

 

[Fishermark]

Re: Total Noob Motor Questions

that a lot more involved than I though it was going to be. Not as advertised by Ignitor!

You're making this more complicated than it needs to be! Simply bypass the positive wire that was leading the coil - that's the reisistor wire. Replace it with a wire that has a full 12v - one that comes from your ignition switch. (That way you can cut off your engine when you want to ) You can run a wire all the way from the switch if you want to. It is easier, and uses less wire, to just cut the wire as mentioned above and splice into it.... but whatever way is easiest for you.

And go ahead a buy a new internally resisited coil. Yes, you can even use an automotive coil if you want to.

 

[cheburashka]

Re: Total Noob Motor Questions

An even easier solution is to keep the purple wire attached to the coil, and to find a switched positive wire. There's no reason to draw your power from the coil lug. It can come from an switched positive source. I used one of the lugs on the starter solenoid. I think the Pertronix instructions explain this process.

 

[Maclin]

Re: Total Noob Motor Questions

Ok, that last post of mine may have been like trying to take a drink from a firehose:redface: I was trying to empasize the fact that there is primary ballast resistance in front of the coil that must be considered...and that there are options ranging from simple to not so simple involving new parts and permanent rewiring.

I will side with cheburaska's advice.....All that needs to change is to power the pertronix from another point. No coil change, nothing else. Should be good to go after that.

 

[cheburashka]

Re: Total Noob Motor Questions

Ok, that last post of mine may have been like trying to take a drink from a firehose:redface: I was trying to empasize the fact that there is primary ballast resistance in front of the coil that must be considered...and that there are options ranging from simple to not so simple involving new parts and permanent rewiring.

I will side with cheburaska's advice.....All that needs to change is to power the pertronix from another point. No coil change, nothing else. Should be good to go after that.

Did you ever check the timing?

 

[Maclin]

Re: Total Noob Motor Questions

That was directed at the original poster, right? He will need to do that once the wiring is correct.

I forgot myself with my "should be good to go"....sorry if I misled.

The location of the trigger inside the distributor changes so it must be timed after the change to Pertronix.

 

[wil7483]

Re: Total Noob Motor Questions

I put in a Pertronix unit in my Mark Twain I had a few years back and had similar problems as you, It would start but as soon as I gave it gas it would backfire, shoot flames and cut off. Guess what the problem was? The timing had to be reset to match the new ignition. If you haven't yet checked the timing then that is where I would look next. I bet it will fix the problems you are having. Sometimes you don't have to look for the most complex solution to a problem. Try it and tell us what happens.