which coil?

I'm rescueing a '64 gas B-414. runs rough. so I've picked up some ignition parts. My question is; should I use a coil with a resistor or not? the existing coil is a Lucas as is the distributor. On casual inspection I can see no external resistor mounted. spark plugs are champion L-90C's, spark plug wires are green with Champion embossed on the 90 degree sparkplug connection. Existing Lucas coil is marked at the bottom as follows: 12V LA 12 o45053N 11 63

I'd get the internal resisted coil. You'll have no problems running it. I always replace coils with the internal resisted ones and have had no problems.

Contrary to what most lay persons think, on most of the circa 30's through 60' typical farm tractor ignition coils THERES NO DISCTRETE STAND ALONE "RESISTOR" HIDDEN AWAY SOMEWHERE INSIDE THE CAN.

There are coils designed for use at 6 volts nominal that can still produce a spark at cranking voltage which may be 4.5 volts yet still produce a spark and dissipate the heat at charging voltages of 7 BY THE WAY THOSE ARE LABELED 6 VOLTS. Many (not all) typical 6 volt coils have 1.25 to under 2 ohms LV Primary winding resistance 1.5 is common

There are coils designed for use at 12 volts nominal that can still produce a spark at cranking voltage which may be 9 volts yet still produce a spark and dissipate the heat at charging voltages of 14 BY THE WAY THOSE ARE LABELED 12 VOLTS. Typical LV primary winding resistance is in the range of 2.5 to 4 ohms, 3 is common

I dont think you will find any coils labeled
6 ORRRRRRR 12 volts !!!!!!!!!!!

THE EXTRA RESISTANCE IN A 12 VOLT COIL IS DUE TO MORE WIRE LENGTH OR HIGHER RESISTIVITY WIRE NOTTTTTTTTTT BY TUCKING A "RESISTOR" INSIDE THE CAN

ANSWER If its a 12 volt tractor you can EITHER use a 12 volt coil orrrrrrrrrrrrr use a 6 volt coil with a voltage dropping (12 to 6) extrenal ballst resistor therefore the coil sees only the 6 volts it was desgined to handle. T^here can be an advantage for cold starting if you use a 6 volt coil but by pass it while cranking !!!!!

Many 6 or 12 volt tractors still use the same 6 volt coil, its just that if on a 12 volt tractor they add the ballast

Got it?? Have to run to the Fair I will check back later for any questions

John T

NAPA part number IC14SB

thanks guys! I just picked up an internal resisted coil. Now i'm headed out to install.

John, you aren't going to win. They still are going to call them internal resisted coils. Something like all track crawlers are cats.

(quoted from post at 20:50:50 07/29/12) . Something like all track crawlers are cats.

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You mean their not???? :twisted:

Where would you get a custom built internal resistor coil? There is no such item on the Napa or other parts counters.
12V coils have twice the number of windings on the primary as a 6V coil.

LOL Im not trying to win, just trying to help and enlighten the folks here how coils are built and how they work, if they choose to believe otherwise even if wrong, its no skin off my nose, but I still try n help the good folks here anytime I can

John T