LUC timing the magneto

nashranch

Well-known Member
I pulled of the magneto shortly after i got this LUC cuz the engine was stuck. I now have the engine turning over good and ned to put the mag back on but don't know how to install it in the correct location. I have found the D/C mark and the PARK markings on the flywheel. Any Help would be appreciated.
 
(quoted from post at 06:31:38 07/31/20) I pulled of the magneto shortly after i got this LUC cuz the engine was stuck. I now have the engine turning over good and ned to put the mag back on but don't know how to install it in the correct location. I have found the D/C mark and the PARK markings on the flywheel. Any Help would be appreciated.

I used google to search on the subject of your post "LUC timing the magneto" and found multiple hits. including the first one which has this text:

Magneto Timing for John Deere L & LA tractors :

1. Loosen the timing cover to see inside timing hole.
2. Remove the mag dist. cap.
3. Turn engine clockwise slowly until you hear the impulse trip. Stop.
4. Then turn slightly counter clockwise until you see the spark mark on flywheel in timing hole and it lines up with mark on center of timing hole.
5. At this place the points should just be beginning to open.
6. If not beginning to open loosen nuts on mag and rotate mag inward or outward until points just begin to open and then tighten nuts on mag.
If that doesn't work to time with mag removed:
1. With timing hole open turn engine clockwise until spark mark is on the center of the timing hole.
2. Remove mag dist. cap.
3. Turn mag gear counter clockwise until dist. rotor is in 10 o'clock spot and then back clockwise until points just begin to open and dist. rotor is in 8:30 o'clock spot.
4. Hold mag in this position while installing on tractor and it may be necessary to turn some to align the gears and then tighten nuts.
5. If timed properly and when crankshaft is turned clockwise until the impulse trips the D.C. mark on flywheel should be at the lower edge of the timing hole when impulse occurs.
Instructions - operators manuals and parts catalogs are available from JD Publications at 1-800-522-7448 or through your dealer or by visiting the JD Tech Publications site. http://techpubs.deere.com
DIR206 Instructions for JD L tractor
DIR207 Instructions for JD LA tractor
DIR208 Instructions for JD LI tractor
PC150 Parts Catalog for L tractor
PC151 Parts Catalog for LA & LI tractors
 
Get it set so that d/c mark is even with the bottom edge of the timing window hole when it sparks to cylinder # 1 which is the one closest to the fan. This will help prevent kick back when cranking as it makes it fire a little after dead center. TDC is when the D/C mark is in the center of the window. Spark mark would be running timing and could be checked with a timing light. Only thing I can't remember off the top of my head is which terminal is recommended to be # 1 on the mag.
 
Mag is back on and timed correctly. This engine was stuck pretty bad but i was able to get it loosened up. Several of the valves were stuck open too so i pulled all the valves to check them out. They were not pretty. I hand lapped them in. used the old head gasket and put all back together. I get 45 PSI in both cylinders after a dab of oil in each cylinder. I know not good. It of course does not start hand cranking. I even tried reversing spark plug wires thinking i was 180 out. Looking more like a boat anchor
 

Yep there is suction but missing on #1 I think. Barely any compression on #1 again since I've been cranking on it. Cylinder #1 is not in good shape. Right now I have carb apart.. need to order gasket kit. It may have been plugged up too. Never saw any wetness on plugs
 
After spending too much time trying resurrect this LUC I have decided to S can this project. Engine was stuck pretty bad, I got that unstuck but surely the rings are wore out. Also valve seats were badly pitted so i borrowed some old valve grinding tools from my neighbor and tried to clean up the valve seats. 3 outta 4 cleaned up ok but the #1 exhaust seat was really bad. I kept grinding away at it but never could get even a new valve to seat. Now it needs a insert installed to save it. Probably too costly to have a machine shop tackle it. So now i have a JD boat anchor with a good Wico X mag and a good M/S Carb and new set of valves. Also a good wide belt pulley drive unit. I would assume the crank is good too. Anybody needing anything off this anchor please PM me. I will ship the small stuff to ya
 

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