Volfandt
Veteran Member
To add to this great discussion on how the battery ignition system works. Back in the day, I was taught that the condenser has two purpose's in the ignition circuit.
To keep current from arcing across the open points by absorbing the voltage when the points open -and- to provide reverse current flow through the coil so a high voltage can be induced into it's secondary windings.
In basic electronics, a capacitor will charge in one direction and discharge when the polarity is reversed in the other direction.
How the polarity gets reversed in a battery ignition circuit is due the the stored voltage in the capacitor reaching a higher potential than the 12v battery voltage that charged it. If one subscribs to theory that current flows from neg to pos, or less pos to more pos, or more neg to less neg, then current flows though frame ground through the closed points, to the condensor, through the coil, through the ign switch to battery pos.
When the points open, battery pos is now more negative than the condensor so current now flows from battery pos through the coil to the condensor. In effect reversing current flow through the coil, producing a square wave ac voltage.
The coil acts like a step-up transformer in this circuit. As 12vdc passes through the primary windings, it produces flux lines which passes through the coils secondary windings. When the current flow stops then reverses flow through the primary windings, a higher voltage is induced into the coils secondary windings which is then routed to the spark plug. There are roughly 10 times as many secondary windings as there are primary windings and this is how it steps up the induced voltage.
Course thats old school, could be new school has superceed it now
As to the OP's original problem. I would recommend rebuilding the carb 1st. A sticking float valve will allow too much fuel to get into the carb which will also find it's way into the intake, flooding out the works.
Could be the valves too. I had an old K181 in an 856 WH that was gradually loosing power, getting harder & harder to start and smoking more at cold startup. A new piston, rod and rings along w/ a good cleaning and lapping of the valves has made it a new engine. I probably cranked the high speed needle in a full turn to lean it out afterwards.
If it's a Kohler K in that JD then it's definitely easy and not too expensive to rebuild.
In any case good luck and get the easy fixes out of the way 1st
To keep current from arcing across the open points by absorbing the voltage when the points open -and- to provide reverse current flow through the coil so a high voltage can be induced into it's secondary windings.
In basic electronics, a capacitor will charge in one direction and discharge when the polarity is reversed in the other direction.
How the polarity gets reversed in a battery ignition circuit is due the the stored voltage in the capacitor reaching a higher potential than the 12v battery voltage that charged it. If one subscribs to theory that current flows from neg to pos, or less pos to more pos, or more neg to less neg, then current flows though frame ground through the closed points, to the condensor, through the coil, through the ign switch to battery pos.
When the points open, battery pos is now more negative than the condensor so current now flows from battery pos through the coil to the condensor. In effect reversing current flow through the coil, producing a square wave ac voltage.
The coil acts like a step-up transformer in this circuit. As 12vdc passes through the primary windings, it produces flux lines which passes through the coils secondary windings. When the current flow stops then reverses flow through the primary windings, a higher voltage is induced into the coils secondary windings which is then routed to the spark plug. There are roughly 10 times as many secondary windings as there are primary windings and this is how it steps up the induced voltage.
Course thats old school, could be new school has superceed it now
As to the OP's original problem. I would recommend rebuilding the carb 1st. A sticking float valve will allow too much fuel to get into the carb which will also find it's way into the intake, flooding out the works.
Could be the valves too. I had an old K181 in an 856 WH that was gradually loosing power, getting harder & harder to start and smoking more at cold startup. A new piston, rod and rings along w/ a good cleaning and lapping of the valves has made it a new engine. I probably cranked the high speed needle in a full turn to lean it out afterwards.
If it's a Kohler K in that JD then it's definitely easy and not too expensive to rebuild.
In any case good luck and get the easy fixes out of the way 1st
