Bass, you say "I found that i have power on one side of the coil. its the side that the wire from the ballist resistor to the coil. no power on the side the runs to the dist. so im guessing the coil is bad
ID GUESS YOUR GUESS IS WRONG as sure coils can go bad, however, what you found IS CORECT AND NORMAL as points are usually CLOSED.
The only time the points break open is when a cylinder is at the top of its stroke and when you shut a tractor off it seldom stops at that location due to compression THEREFORE since the points are likely CLOSED the NORMAL condition would be to have voltage on the coils INPUT but near zero volts on its OUTPUT (to distributor then ground via closed points) since the points are closed to ground. SO WHAT YOU DESCRIBE DOES NOTTTTTTTTTTTTT MEAN THE COIL IS BAD AS YOU GUESSED.
Put a test lamp or voltmeter on the coils output (or dist terminal) and turn ignition on and lowly turn the engine over... The light should go ON when points are open but OFF when they are closed. If its cranked over the light on coils output will flash ON and OFF. A) If it never goes ON the points aren't opening,,,,,,,,,,Or theres a short from coil to points such as the pass thru insulator bushing on side of distributor or points them selves or its wire,,,,,,,,,,,,,,,OR the condenser is shorted out,,,,,,,,,,,,,,,,,OR sure the coils LV primary winding is open and the coil is bad. B) If it never goes OFF, points aren't closing or badly burned and corroded,,,,,,,,,,,,OR wires open from coil to points,,,,,,,,,,,,,OR dist isn't grounded.
If the light comes on (Ign on of course) with points OPEN or better yet just unhook the wire off coil that goes to dist. THE COILS LV PRIMARY IS NOTTTTTTTTTTTT OPEN. More common coil problem is HV breakdown in the HV Secondary wiring once warmed up.
My Test Procedure linked below describes how to bench/tractor test a coil all by itself and by pass any points or dist problems. If the coil has power each time you jump the output to ground then remove it (replicates points closing and opening) A GOOD COIL PRODUCES A HV SPARK you can see if you have the HV top output wire to within 1/4 inch away from frame ground
Unhook everything and use an ohm meter on the low ohms scale across the coils LV primary little + and - terminals. It should be from 1 to 4 ohms and NOT an open circuit infinity ohms which means the coils is bad and open.
If you want to know how to easily determine the cause of no fire (and check coil and points and condenser etc) with only a test lamp or voltmeter or even no tools whatsoever other then a way to open and close the points and observe and KEEP IT SIMPLE you have to work through my Ignition Troubleshooting Procedure step at a time. It has other SIMPLE helpful hints and shortcuts and tests so you dont have to throw parts at it or keep guessing as you have done.
The more common (instead of a bad coil) cause of no fire is points that are burned or pitted or not fully closing or points or wiring that's shorted out or a bad condenser.
Click the URL link below or copy and paste this link into your browser for simple easy methods and test procedures (requires little or no equipment) to find the problem.
http://www.ytmag.com/cgi-bin/viewit.cgi?bd=farmall&th=5745
Post back any questions, best wishes, God Bless and good luck
John T
Simple easy checks to find cause of no fire
