Best guess; The yellow wire on the engine goes to the white wire on the tractor for lights.
The black wire on the engine goes to the red wire on the tractor for charging.
Do not use the green wire on the engine.
Your Lt12 diagram doesn't show a switched 12VDC but that's what you need for the red wire on the engine.
Not shown on the diagram but the "M" terminal on the switch is usually a Ground in the Off Position to kill the engine. That would go to the white wire on the engine, it should never have 12VDC+ on it.
Again these are best guesses. I have done this several times but I always double check things with a test light.
Are you sure you have the Smart Spark ignition?
Correction, I do see a yellow wire on the diagram from the "
M" terminal the the magneto. I think it would go to the White wire on the engine.
Cannon
The black wire on the engine goes to the red wire on the tractor for charging.
Do not use the green wire on the engine.
Your Lt12 diagram doesn't show a switched 12VDC but that's what you need for the red wire on the engine.
Not shown on the diagram but the "M" terminal on the switch is usually a Ground in the Off Position to kill the engine. That would go to the white wire on the engine, it should never have 12VDC+ on it.
Again these are best guesses. I have done this several times but I always double check things with a test light.
Are you sure you have the Smart Spark ignition?
Correction, I do see a yellow wire on the diagram from the "
M" terminal the the magneto. I think it would go to the White wire on the engine.
Cannon