I have a 1942 John Deere LA and am having trouble timing the mag.
The instruction in the book is rotate crankshaft clockwise untill impluse occurs then rotate counterclockwise untill spark mark on flywheel shows in timing hole .
The mag. points should be beginning to opem .
After the mag. is timed the inpulsespark should be checked .
Tturn the crankshaft clockwise until the impulse occurs .
The D.C. mark on the flywheel should be at the lower edge of the timing hole when the impulse occurs .
The impulse occures 3 inches late .
The tractor will not start or fire when primed at the pugs .
All help is appreciated Myron in Ct.
PS If anyone who is familiar with JD LA and would be willing to help please e-mail me .
Full Version: Help Timing Jd - La
Welcome the Discussion Board
Nornally these questions are best answered on the Tractor shed.
I do have a LA but don't have it running and will leave a question mark on some non confirmed items.
But first, on starting do you have spark when cranking the engine? Mine has a electrical kill to the Magneto which is a little tricky on/off.
Has the engine been torn down since it last run that timing gears may wrong?
My method to time and fine tune later.
1. Loosen the mag enough to turn that top of the mag is near the engine.
2. turn the engine by the crank at least one turn til the #1 cylinder ( front cylinder ?)comes up on compression for top dead center (DC)
3. turn the magneto out away the engine slowly til the impluse snaps.
4. you should be in time tighten the bolts.
5. install the wires #1 cylinder to terminal closest the engine ( That the way I found mine but I haven't confirmed correct)
6. hopefully tthe engine will start and you adjust the carburetor if needed and adjust the mag a little forward and back to get peak performance.
7. if have to repeat step 3 start with step 2 cranking the engine clockwise.
Good luck and work safely
Nornally these questions are best answered on the Tractor shed.
I do have a LA but don't have it running and will leave a question mark on some non confirmed items.
But first, on starting do you have spark when cranking the engine? Mine has a electrical kill to the Magneto which is a little tricky on/off.
Has the engine been torn down since it last run that timing gears may wrong?
My method to time and fine tune later.
1. Loosen the mag enough to turn that top of the mag is near the engine.
2. turn the engine by the crank at least one turn til the #1 cylinder ( front cylinder ?)comes up on compression for top dead center (DC)
3. turn the magneto out away the engine slowly til the impluse snaps.
4. you should be in time tighten the bolts.
5. install the wires #1 cylinder to terminal closest the engine ( That the way I found mine but I haven't confirmed correct)
6. hopefully tthe engine will start and you adjust the carburetor if needed and adjust the mag a little forward and back to get peak performance.
7. if have to repeat step 3 start with step 2 cranking the engine clockwise.
Good luck and work safely
QUOTE(OCB @ Apr 18 2008, 05:08 AM) 
Welcome the Discussion Board
Nornally these questions are best answered on the Tractor shed.
I do have a LA but don't have it running and will leave a question mark on some non confirmed items.
But first, on starting do you have spark when cranking the engine? Mine has a electrical kill to the Magneto which is a little tricky on/off.
Has the engine been torn down since it last run that timing gears may wrong?
My method to time and fine tune later.
1. Loosen the mag enough to turn that top of the mag is near the engine.
2. turn the engine by the crank at least one turn til the #1 cylinder ( front cylinder ?)comes up on compression for top dead center (DC)
3. turn the magneto out away the engine slowly til the impluse snaps.
4. you should be in time tighten the bolts.
5. install the wires #1 cylinder to terminal closest the engine ( That the way I found mine but I haven't confirmed correct)
6. hopefully tthe engine will start and you adjust the carburetor if needed and adjust the mag a little forward and back to get peak performance.
7. if have to repeat step 3 start with step 2 cranking the engine clockwise.
Good luck and work safely
Nornally these questions are best answered on the Tractor shed.
I do have a LA but don't have it running and will leave a question mark on some non confirmed items.
But first, on starting do you have spark when cranking the engine? Mine has a electrical kill to the Magneto which is a little tricky on/off.
Has the engine been torn down since it last run that timing gears may wrong?
My method to time and fine tune later.
1. Loosen the mag enough to turn that top of the mag is near the engine.
2. turn the engine by the crank at least one turn til the #1 cylinder ( front cylinder ?)comes up on compression for top dead center (DC)
3. turn the magneto out away the engine slowly til the impluse snaps.
4. you should be in time tighten the bolts.
5. install the wires #1 cylinder to terminal closest the engine ( That the way I found mine but I haven't confirmed correct)
6. hopefully tthe engine will start and you adjust the carburetor if needed and adjust the mag a little forward and back to get peak performance.
7. if have to repeat step 3 start with step 2 cranking the engine clockwise.
Good luck and work safely
Thank you OCB
I do have spark because I have a spark tester on the plug .
I don't think the has Been worked on because of the paint and grease .
I will try your method of timing .
Thank you OCB
Myron in Ct.
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