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Fri Nov 21, 2008 2:21 pm

i recently just bought a msd blaster 2 coil. i hooked it up and my bus was able to run but it ran like crap, was miss firing and flames were shooting out of my stinger. i tried adjusting the fuel mixture and the timing somewhat but could not get it to not back fire.

i put this on a 1914 with dual carbs. i dont know the cam,crank, and wat the timing is set at now. any thoughts?

Fri Nov 21, 2008 2:58 pm

Did you use the resistor that comes with it? You may have fried the electronics in your distributor without it unless you are running some sort or ignition box.

Fri Nov 21, 2008 3:50 pm

That particular coil requires an ignition box, doesn't it?

Fri Nov 21, 2008 3:57 pm

If your running points & a condenser. They are dead now. Check & make sure the wires are on in the right order & not fried. Make sure the cap & rotor are FACTORY BOSCH. The cheep caps will cross fire with any kind of voltage. like the 40,000 volts the MSD puts out. Don't forget to regap your plugs to about .40 thou. Make sure your using non-platnum plugs. NGK plugs are the best with MSD. Set your timing at about 30 - 32 degrees total.

Fri Nov 21, 2008 3:59 pm

manxracer1 wrote: If your running points & a condenser. They are dead now. Check & make sure the wires are on in the right order & not fried. Make sure the cap & rotor are FACTORY BOSCH. The cheep caps will cross fire with any kind of voltage. like the 40,000 volts the MSD puts out. Don't forget to regap your plugs to about .40 thou. Make sure your using non-platnum plugs. NGK plugs are the best with MSD.

If he's just running the coil with no box, it's not going to put out that much voltage by itself. If he has a box too, and has a stock rotor, it's probably getting burned up.

Fri Nov 21, 2008 4:26 pm

The Blaster 2 coil has a 0.7 ohm primary resistance and if it is used with points or most ignition modules, it will require a external ballast resistor, or you may damage the points, ignition module or even the ignition coil itself!

The resistance value of the ballast resistor is dependent upon the ignition module or points that are going to drive it. So read the manufacturers instructions.

Many, if not most external ignition systems don't require a ballast resistance, as they control the primary current internally.

Hopefully you haven't damaged your coil, ignition module or points.

Resistive ignition wires and resistor rotors increase the voltage inside the distributor cap and should not be used.

Always use low loss magnetic suppression ignition wire and a resistorless rotor or a resistor rotor that has been modified to bypass the resistor.

Provided that you are using a resistive rotor and low loss magnetic suppression ignition wires, changing the ignition coil will not cause crossfiring problems unless you also increase the spark plug gap. Your spark plug gap determines the maximum voltage inside the distributor cap, NOT the ignition coil, unless the ignition coil is very weak.

Blue streak makes a distributor cap that is superior to Bosch. I believe that CB performance is having their "Magnition" distributor caps made for them by Blue Streak.

Scott Novak

Fri Nov 21, 2008 5:07 pm

For the cost of a couple caps you could get the MSD distributor & be done with it.

Fri Nov 21, 2008 6:43 pm

manxracer1 wrote: For the cost of a couple caps you could get the MSD distributor & be done with it.

if the OP was just springing for a coil upgrade(or so he thought), it's not likely that he wants to go with the MSD distributor and box..

Sat Nov 22, 2008 9:19 am

i was thinking to get that coil too,i have Compu-Fire ignition module inside bosch 009, i have NGK plugs and 10mm powerblast ignition cables,i think they are quad core

will the coil work with my system?

Mon Nov 24, 2008 11:15 am

ya come to find out i do need the box with it. and it did fry the points but not until a couple days later after i replaced it with my bosch coil. finally burned this morning wen i was gonna go to skool. wouldnt start.

thanks guys

Mon Nov 24, 2008 11:29 am

You can run that ignition coil with points as long as you connect an external ballast resistor to the ignition coil Positive terminal. When you do this, the ONLY connection to the ignition coil Positive terminal will be the ballast resistor. The other end of the ballast resistor connects to the ignition keyswitch wire, and electric choke, and the electromagnetic cuttoff valve on the carb if you are using a stock carb.

Scott Novak

Mon Nov 24, 2008 12:16 pm

Waaaaay back when I was rodding American iron this coil came with a ballast resistor for use with points. Is this no longer true?

Mon Nov 24, 2008 12:19 pm

so can i use it with CompuFire Ignition module or not?

is it safe to bypass the rotor resistance or it will hurt anything else or shorten its life?

Mon Nov 24, 2008 2:25 pm

Absolutely use a resistorless rotor, or a rotor with the resistor bypassed. The only purpose for the resistor is radio noise suppression. Using resistance to suppress radio noise is one of the poorest ways to do it. But it's also the cheapest.

The same applies to resistor spark plugs, which reduce radio noise at the expense of performance and gas mileage. The resistance only degrades your ignition performance. So also use non-resistor spark plugs.

Use 8 mm or larger diameter low loss spiral wound magnetic suppression ignition wire and you will not have any radio noise problems and you will have maximum spark power to deliver to your spark plugs.

Avoid using multicore ignition wire. It is snake oil and the additional cores do NOT improve performance. In fact they may actually hurt the overall performance.

By using low loss ignition wires and a resistorless rotor, the voltage losses are reduced enough that you can increase your spark plug gap by about 0.005" for improved performance.

You can use almost any ignition coil with a Pertronix Ignitor 1, Compufire, Computronix, Hot Spark, Mallory Unilite or Mallory MBI ignition modules, as long as you have enough total ballast resistance.

Pertronix Ignitor 1, Compufire, MagnaSpark, Hot Spark all require a minimum of 3 ohms of ballast resistance, and Mallory Unilite and Mallory MBI ignition modules require 1.4 ohms ballast resistance minimum.

Example, if you are using a Pertronix Ignitor 1, Compufire, Computronix, Hot Spark ignition modules, and your ignition coil has a 0.7 ohm primary resistance, you need to use an external ballast resistance of 2.3 ohms, which would be a total 3.0 ohms resistance.

Example, if you are using a Mallory Unilite or Mallory MBI ignition module and your ignition coil has a 0.7 ohm primary resistance, you need to use an external ballast resistance of 0.7 ohms, which would be a total of 1.4 ohms resistance.

You could use the same ignition coil with any of these ignition modules as long as you use the correct external ballast resistor.

There is no performance advantage to using an ignition coil with an internal ballast resistance. In fact, the extra internal ballast resistance just makes the ignition coil run a little hotter.

An ignition coil without a ballast resistor also allows you to use the ignition coil with a capacitive discharge ignition system. Using an ignition coil with an internal ballast resistance causes large voltage losses when used with a capacitive discharge ignitiion system.

As an experiment, I added external ballast resistance to a Jacobs Ultra coil to equal a total of 3.0 ohms. The output voltage and current dropped by over 16%.

Scott Novak

Mon Nov 24, 2008 2:31 pm

Viande wrote: Waaaaay back when I was rodding American iron this coil came with a ballast resistor for use with points. Is this no longer true?

IIRC, that coil can be ordered with or without the ballast resistor.