Coil amp.and volts

Hello. Now I have measured my coil in the purpose of low reving 289".
I have the standard loom resistance wire and the volts are 9.8v at idle and 11.8v when it´s been reved up. Is that okey?
The coil draws between 1to7 amperes on the primary side is that okey to?
The ignition is a mallory mbi distr. and a mallory crome coil.
Thank´s Gresse

Your coil sounds like its workign correctly to me. [img]/forums/images/smiles/icon_smile.gif[/img]
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P.S. The coild doesn't draw the amps... The points adn condensor draw the amps.

FE
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A coil definitely draws current. The primary side generally has low resistance and when the points or electronic ignition module is closed, there is current flowing thru the primary side winding. If you have a 1.5 ohm resistance wire and a 1.5 ohm coil winding, at 12V there will be 4 amps flowing. When the points open, the magnetic field collapses in the coil and a ton of voltage is generated on the secondary side and a spark is generated.

Are you measuring the current while the engine is running? Does the voltage at the battery also increase by 2 volts when you rev the engine?
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Thank´s. I am just a little electric confused.
I have been told to measured the amps on the primary side because the pertronix coils "draws"20 amps and over 5000 they don´t have the time to charge.(something like that)Seems like my mallory coil don´t
"draw" that much so I can continue the search for my lost revs.
Thank´s Gresse

You just posted before me.
I ran out to the garage right the way and take another measurement.
Yes I measured when the engine was running and the volt on the battery hold a steady 14.9volts! Seems a little high don´t you think?
Thank´s Gresse

14.9 volts is fine..... maybe your meter is reading .5 volts to high... but it is fine.

Points are an on/off switch... they do not use power or current. The condensor/capacitor looks like an open circuit to a DC voltage, so it does not pull any current either.

The Coil is the only item that draws current.

It is difficult to measure the primary current directly, with the engine running. Since the current is pulsed and not a steady current, you must use an oscilloscope to know what the real current is. Using a current meter will only average the actual current reading.

A safer and easier way to figure the primary current is to measure the resistance of the coil. A standard coil will measure about 1.1 to 1.4 ohms Or at 12 Volts applied over 1.2 ohms = volts/ohms = 10 amps

Petronix coils are .5 to .7 ohms 12 volts / .6 ohms = 20 Amps.

Your coil sounds fine. If your loosing power over 5000 rpms, it is probably something else, maybe your carb is not jetted correctly, not enough gas getting to the motor, or your total timing at 3000 RPM's is too far off.

<font size=-1>[ This Message was edited by: Mikes66 on 3/28/07 1:05am ]</font>

Okey. I have stepped up to 66 front 80 rear jets and I felt it got more tourqe now,but if it reved any higher hard to tell.
My total timing was 38* I will try 34* and see if it likes that.
Thank´s Gresse

If you're running points the voltage at the coil + should be full batttery voltage only at startup, comes from the starter solenoid during cranking. When the key is returned to "run" position the coil gets it's power through the resistor or resistor wire which is usually about 3 volts less to keep from burning the points.
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Thank´s.I got it.It seems to be okey.
More problems.I have not touch anything and all of a suddent my timing shows 30*at idle and 50*at 3000rpm.My balancer is a 2year old sfi approved unit.Don´t think it have slipped.Have to do some more measurements and try to figure out what is wrong.
Thank´s Gresse