Bought the MSD Hi-Vibration Balster coil to replace my stock one. Do I need a ballist with this one or is it only for distribs that have points? All other ignition is the stock Merc.
Thanks

Jerry, I think you are correct. The resistor should be for points only. I have a MSD Blaster coil on my 500 with all else stock Merc. Worked great last season and I'll put it on this season as soon as the motor gets back here.

Eric

ballast resisters are only needed for points. if it was converted from points to electronic the resister has to be removed to get at least 12 volts to the coil or the ignition module will be damaged.
not all had ballast resisters though. some had resisters wires to lower the voltage after startup so the points wouldn't burn up. same thing though, just find it and cut it out or replace the wire.
Fran

brad perry was nice enough to send me his spare blaster coil and i have an MSD box. I am addign this to my setup this year. I am running a thunderbolt 4 ignition am i goignt o need one of these ballast resistors?

Puder.......Nope. Not unless you are using a actual point set. With that you have the ballast resistor (or wire) inline to the (+) on the coil, which drops the 12v down to about 7voltish. (otherwise you would burn out the point contacts).

Thanks guys! So no resistor.

Also think I found my problem of why my motor missed out under load 2 weeks ago while on the dyno. Apparently over the winter while the motor was apart and the distrib was laying on the floor, some oil must have ran up the shaft, into the cap and into the pickup. Rotor had an oil film on it. Oh well,...... new cap, rotor, coil and wires. Was all original '94 anyway. So now good to go!

Jerry

i gotcha! cool