mercuriser 1985 5.7L engine. coil marked "use with resistor"

[grewvin1]

1985 twin merc. 5.7L engine, rebuilt carb. new dis. cap rotor ignition pick up module new wires new plugs, new coil. engine ran great for 6 hrs then craped out. Backfire through carb at high speed or load, would only run at 2000 rpm. Changed coil ran great again but noticed on the removed coil and the new one stamped "use with resistor" Is this right? I don't belive I have an external resistor will the coil break down again?

 

[achris]

Re: mercuriser 1985 5.7L engine. coil marked "use with resistor"

That engine should be running Thunderbolt IV ignition system... .Any coil will do... I would use a GT40... http://www.sonicperformance.com.au/GT40/Bosch-GT40-Ignition-Coil/pd.php (they'll be cheaper in your part of the world :facepalm

Chris.......