where’s the ballast resistor?

I've had a Pertronix Ignitor and now have a Unilite distributor in my 78 Nautique and both have a current requirement via the ballast or resistance wire to the coil. One wire to the distributor module ( in both cases the negative terminal ) must not see to much current.

I use a MSD Blaster 2 coil which has .7 ohms internal resistance and I run a .8 ohm ballast resistor to make 1.5 ohms - resistor and coil combined. Points need a ballast or resistance wire or a coil with 2 to 3 ohms resistance in it so the points don't burn to quickly.

The timing sounds about right, 10 BTDC and around 30 degrees at 3000 rpm, I'd be happy with that. Check the directions for the type of electronic ignition you have for the resistance it needs, I can't think of something else from just changing the distributor if the timing is correct - except the carb gasket and if you use a PVC spacer under the carb make sure you get a gasket the covers the whole spacer or here come a vacuum leak, bad idle and maybe running hotter than usual.

Thanks for the feedback. I've traced the wires from the coil to the relay and I can't find a resistor. When you mention vacuum leak, do you mean at the intake mainifold/throtle body? I know I've got a problem there. But, I don't have any vacuum lines coming off the carb. Is this normal?

The boat is at the lake so I won't be able to check rotor position for a couple of days. I re-read my orriginal post. I didn't replace the distributor, only the cap, rotor and ignition module.

Jimbo:

I once tried combining a GM HEI ignition module with a Ford magnetic pick-up distributor. I read about this conversion on high performance Ford autos. Well, short of the story is that the engine ran like crap...just like you are describing. Idle quality was non-existant and just overall bad results. I messed around with it for the better part of a full day and finally junked the whole thing and put my old distributor (points) back in and the engine ran perfect.

I also bypassed ballast resistor, change coils all to no avail. I would love to have figured out what the problem was, but just got frustrated and quit. So, I am anxious for you to figure it out. Next time I may go Pertronix, but my experience makes me a bit nervous. I know I was trying a bastardize setup, but strange never-the-less. Sorry that this post is no help at all, just another persons similiar experience.

Oh, one last thing. I played with the timing until I was blue in the face. I must have pull the distributor 10 times to make absolutely sure I had it correct...even installed with rotor in a position that I was sure was not correct to confirm. ARGH!

What I meant by vacuum leak is the intake gasket letting the engine suck in air. Not a vacuum line.

jimbo, my '78 COMMANDER doesn't run a ballast resistor, but rather, a resistor WIRE (like some automotive applications). So... if you need to run without resistance, you will HAVE to run a new wire (at the full 12 volts). You should be able to identify whether you have a resistor wire in a few different ways: it will probably be WAY too long (and coiled back-and-forth in your harness); it may be labeled on the insulation; if all else fails, check it with a volt meter (if it doesn't have full voltage then it is a resistor wire).

Kenny:

Apparantly, some (or one) of the Pertronix retrofit modules needs the resistor. I made the same statement as you and was soon admonished (nameless person) rather than corrected. So, I will politely (I hope) correct you and suggest that people read the manual that comes with the electronic ignition kit to determine if the resistor is required or not.

Which coil did you order? I got the one Accel makes for high vibration and heat since it sits on the intake. This coil has a gel inside instead of oil.

How was the engine running before the ignition conversion? If it was running OK, I don't think the coil is the problem. Check the voltage on the wire feeding the coil. If it is less than 12 volts, then you are getting some resistance from somewhere - probably from a "resistor wire". My conversion kit allows the resistance to remain, so I only have about 9 volts feeding my coil, but if you need 12 and you only have 9, it will run like crap - just like you described in your original post; it will have a very weak spark.

No takers?

I don't know 66polyhead, I can't agree with your post, how does your advance curve change with a electronic conversion?, that's a weight, spring and RPM controlled function.

My opinion is electronic ignition is far better than points. We all have our preference.

Allright, I'm verry well versed w/ this info because I have converted my 351 commander to a mallory mbi ignition. I have the mallory distributer ylm5544cv and a balist resister. All ignitions have or should have a loom risisted ignition wire or a ballist resistor between the ignition switch and the positive side of the coil. The perpose is to drop the voltage from the switch prior to the power getting to the positive of the coil. The jumper wire from the starter relay goes straight to the positive side of the coil. No resistance. This gives the ignition system additional power druing starting only and yes you need it. The module in the distributer gets a full 12-14.4 volts at least on a mallory. The coils voltage gets reduced because it ahs the power to store energy which is expelled when the negitive side is triggered by the mbi the green wire from the distributer. Test the power at the switch, then test the power at the inlet to resister and after. It should drop unless damaged. So I hope that explains it. Clean up your grounds also. Oh and to the post up top! The regulator is what limits the voltage over 14.4. The balist resister drops the voltage to between 8-9 volts to the coil. The rectifier (motorolla box) on the back of engine) converts the ac power to dc and then cleans it up for even flow. Good luck.

sound like your getting there. Be sure to check all the voltage to the system. the wire your talking about that has the extra length? I'm not sure what that is. That sounds like it could be a loom resistance wire. Test the voltage at the switch and then at the end of the wire where it would attach to the positive side of coil. It should be at 8-9 volts and no less. If its more the you'll ned the balist resister block. The problem is rarley the coil. It you have given to coil a full 12-14 volts in the past this will damage the module. So be sure your not chasing your own tail. Check the voltage! The check it with the module unpluged. I damaged my module by jumpstarting my boat with a battery charger. All the voltage was great with the module unpluged but when the module was pluged in everything droped to below 3.75 volts. This caused weak spark and a rough idle. Solve one issue at a time. Also check the power valve in the carb. If the motor backfires through the carb the power valve is gone. this cause gas to be dumped in the intake at idle when is should only open up at full power. Is the primary bowl draining while it sits? Good luck.

Do I need the resistance if I converted to electronic ignition? Somewhere I got the Idea that if I convered to electronic ignition I should get rid of the resistance and send as much voltage to the coil and thus to the spark plugs as possible. I thought the resistor was to keep the points from wearing as much. Any ideas on this?
I can't check the voltage until this weekend. I do suspect there could be a problem with a weak spark. I used one of those screwdriver looking spark testers and it wasn't very bright.   I just thought the plug wires might be too insulated to get a bright flash or the light was bad. I never checked the spark indicator on my truck. I can do that before next weekend.

Don't give up on it. You gotta a good boat. I realize you would like to get the boat running and drive it but I strongly advise you fix the manifold leaks before you go any farther. This means pulling off the manifolds, cleaning the machine fits, re-gasketing, and torquing with a torque wrench in proper bolt sequence. The machine fits can be cleaned with a soft wire wheel on a hand drill or with medium grit emery cloth and elbow grease. All of the machine fits must be clean enough to eat off of. A "bottom" tap with a drop of light oil should be ran down each bolt hole to clean the bolt holes and prepare them for new or cleaned bolts. Be sure to use new bolts or wire buff and oil all of the existing bolts to a new spotlessly clean condition.

Bolt kits can be purchased on-line for a fairly low price from people like Summit Racing. This will save you the time of cleaning bolts.

After the leaks are repaired go to work on the ignition.

The people at skdim are helpful. Ask them which coil you need for the conversion kit you bought.

The instructions for my Pertronix Ignitor electronic conversion module state: "Never use a HEI type coil with the Ignitor".

Conventional point type ignitons must have the voltage reduced to the points. This was traditionally done by adding a (ballast) resistor in series with the primary wire (the hot wire) to the coil. The resistor was usually rectangular white porcelyn about 2" long and had a value typically 1.5 to 3.0 Ohms of resistance. The resistance in the circuit would result in lower than 12 volts applied to the points. Coil manufacturers came out with coils that had built-in resistors (resistance actually) that would reduce the voltage without the need of a seperate (external) ballast resistor. So, your system may have had the resistor removed if a coil with a built-in resistor was used. The resistor could have been disconnected and left mounted in place - or it may have been removed, or it may never have been installed if your system came with a coil with a built-in resistor.

High Energy Ignition systems (HEI) use coils that output a much higher voltage to the spark plugs. This is a totally different issue from the resistance required in the primary circuit of older point type ignition systems.

I am not saying you are installing the incorrect coil because I do not know which electronic conversion system you bought.

Check with support at skdim. Tell them you need a coil that will work with the conversion kit you bought. If they recommend a conventional type coil for use with a points type (sometimes called a breaker type) distributor get a coil that DOES NOT require an external resistor. You may hook your 12 volt primary wire (the hot wire) directly to the + terminal on that type of coil.

Keep us posted.

Mine was a little tight too. I could not install the rotor with the spacer on the distributor. I had to press the spacer on the rotor first and then install the rotor and spacer on the distributor as a single unit.

No. I did not have to file it down. I did think for a minute that it was not going to fit - it was very tight. I had to force the spacer part of the conversion kit onto the rotor and then install it as a one-piece assembly onto the distributor shaft. Even then I had to press hard while I twisted the assembly onto the distributor shaft. I would not file it - I would return it first and try a different brand of conversion.

Or you may try a different brand of rotor. Can you take the unit to an auto parts store and try different brands of rotors? (Is that what you have already done?)

All that being said, I am very happy with the Pertronix conversion. The engine runs smoother at higher RPMs. I did not gain any RPMs, a subtle engine miss at high RPMs, that most people didn't notice unless I brought their attention to it, was eliminated. Who would have thought the miss was related to points? - not me. I am now an advocate of the conversion and I was very skeptical.

You should probably try a different brand of conversion.