Posted by Steve@Advance on June 16, 2018 at 20:36:35 from (66.169.147.211):
In Reply to: 2n ford posted by roy prins on June 16, 2018 at 18:08:08:
The reason for the resistors ahead of the coil is to get the amp draw on the points in the correct range to give points long life and get sufficient spark to the plugs.
The goal for a 12v system is to get about 3 ohms resistance across the coil and all resistors.
To check the resistance, you'll need to remove the cap, connect one lead of the meter to the non grounded side of the points (be sure points are open), the other lead to the ignition side of the ignition switch (switch off). What you will be reading is the resistance through the primary side of the coil and all resistors.
If the reading is low, 2.5 ohms or lower, the load on the points will be too great. The coil will over heat, the points will be short lived. But it will have a powerful spark, while it lasts.
If the reading is too high, 3.5 ohms or higher, the spark will be too weak.
A simpler test is to check the voltage at the coil primary terminal. With the points closed, ignition on, with the 12v coil in place should get around 9 volts. The same results will apply, high voltage will give hot spark, but overload the points. Low voltage will give insufficient spark.
My concern is possibly the coil and resistor included in the kit are correct, and there is another problem with spark delivery, like bad wires, rotor, cap, or plugs. By removing the resistor, you upped the spark, but will be overloading the points.
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