WD-9 has no spark

Wd-9 has no spark tried several things..looking for opinions on the cause..thanks..

It has either a magneto, or point and coil help us help you. Jim

It is a 1949 with a mag..

First thing I'd do is disconnect the mag grounding wire that runs between the mag and the switch at the front of the manifold. If the mag now sparks there's a problem with the switch (contacts are not opening when the starting lever is in the "gas" position).

If still no spark, then look for the usual mag problems: dirty/improperly adjusted points, bad condenser, sticking impulse coupling, bad coil, etc.

On the side of the mag there is a connection (actually a grounding "kill" switch connection.
There are two ways the mag is grounded to stop the ignition. One is the push pull button at the electrical box on the steering support. the other is an interconnected ground at the manifold that prevents the mag from working when the tractor is in diesel mode. By removing this wire, and trying to start the tractor, the mag should work. if it does fire, your issue is with those switches to ground (NOTE: there is never any voltage applied to that terminal, it will fry the points in the MAG). If it does not fire, the points (.013" gap) probably need to be cleaned. If cleaning them makes spark connect the wire!
Note: the points are behind the plate behind the rotor. The rotor is timed with small gears to the Mag cam. do not loose this timing when removing the plate under the rotor. Note the position of the rotor exactly on the plate, (mark it!) and do not turn the engine when the rotor drive is removed. Or mark the teeth on the gears to be sure of correct reassembly (if I sound too serious about this I am not. it is easier to have you be careful here than walking you through timing the rotor from an unknown position. Jim