John Deere Model E Engine Restoration

Jonh Deere Model E: From removing the magneto and igniter to timing the magneto and painting it John Deere green


| September/October 1985



Crank side of engine. Flywheel removed for clarity.

Crank side of engine. Flywheel removed for clarity.

The restoration of a John Deere Model E is not much different from most makes of gas engines, however, there are some differences. For the benefit of those who have not had much experience in restoring a John Deere I will explain how I go about it. For this article I will assume that the engine we have aquired has been sitting out in the weather for a long time and that every part on it is stuck. This is the way I have found most of mine.

It is not advisable to turn the flywheels on these engines even if the engine is not stuck. The reason for this is that the magneto or igniter may be stuck even though the rest of the engine is free.

The first step I take in restoration of my John Deere Model E is to remove the magneto from the engine. This is done by first removing the 3 machine screws that hold the magneto cover plate to the crankcase cover. Next, remove the 3 bolts that hold the crankcase cover to the block and remove the cover. Remove the six machine screws from the governor cover (the plate with name and serial number) and remove the cover. If working on a 3 HP engine use care not to lose the spring on the cam follower. It will jump out when the cover is taken off. The 1 and 6 HP engines do not have this spring. The magneto is attached to the engine block with two bolts from inside the governor case up into the base of the magneto. Remove these bolts and set the magneto with gear attached off. If the magneto is not stuck, you can test it with a 6 volt flashlight bulb. I use a 6 volt hunter's head lamp. Attach 1 wire to the terminal of the magneto and the other wire to the body of the magneto. Hold the magneto upright on a flat surface and spin the gear with your hand. If the magneto is strong enough to run the engine, the bulb will burn fairly brightly in flashes. If the magneto is stuck, remove the four screws from the end plate and carefully slide the end plate off the shaft. Remove the nut from the other end of the shaft and using a small gear puller remove the magneto gear from the shaft. Do not use a great deal of pressure with the gear puller. If gear will not come off, spray with penetrating oil and try again in a day or two. When the gear is removed clean the armature and the inside of the magneto body with WD-40 and a cloth, but do not soak the armature of body. Check the collector brush (on top) and the ground brush (in end plate). If these are worn out, replace with new ones. Re-assemble the magneto and if it still does not light up the bulb, take it to a dependable magneto repairman. Caution: The bushings in a John Deere magneto are not pressed in. They are cast into the white metal. Any attempt to press worn bushings out and replace with new one will result in a cracked magneto body and end plate. The only way the bushings can be replaced in a John Deere magneto is for a person with a good turning lathe and a good knowledge of how to use it to turn out the old bushings very thin and make new bushings to fit inside the old ones. Do not attempt to drill out the old bushings with a drill press. The tolerances required for the armature are much too critical for this. If your magneto needs any major repairs, let an experienced repairman do it. You will be dollars ahead.

The next step is to remove the crankshaft and flywheels. First remove the piston rod cap from the piston rod and remove the shims and bearings. Mark the bearings and cap so they can be put back the same way they were. Remove the main bearing caps, shims, and the top halves of the main bearings. Mark all bearings and shims so they can be put back like they were. Lift the flywheels and crankshaft out of the lower main bearings and remove the lower bearings. After this remove the governor and cam shaft. To do this, first remove the speed change nut, then slide the cam shaft follower off its shaft. Remove hookup lever by first removing the welsh plug from the top of the governor case. (under the magneto) Then slide the rod up through the hole under the welsh plug. Hookup lever will then come out. To remove the governor, place a small wooden hammer handle through the spokes of the camshaft gear. This will keep the governor and camshaft gear from turning. Remove the hex nut and washer from the governor. Caution: This nut has left hand threads. Governor will now slide out. It is not usually necessary to disassemble the governor any more than this, but be sure all parts of the governor work freely. Remove the cam shaft from the cam shaft gear by taking off the large hex from the shaft (right hand threads) and using the gear puller, pull cam gear off the cam shaft.

This completes the disassembly of the internal gears of the engine. Now we will work on the head and piston. First, disconnect the gas line from the mixer. Remove the cylinder head by removing the four nuts from the studs. Remove the exhaust lever and spring by taking off the nut on top and unscrewing the bolt that the exhaust lever swivels on. Loosen and free the exhaust lever adjusting screw and free the pivot between the exhaust rod and exhaust lever. Oil the igniter trip bracket, loosen the two clamp bolts that hold it on the exhaust rod and work it back and forth until it slides freely on the rod. Work the igniter trip finger up and down and check the spring that holds the finger up. If necessary, replace the spring with a new one.

Remove the igniter from the cylinder head by taking off the two bolts that hold it to the head. Trip the hammer of the igniter with your finger. If it trips, then push up on the hammer. There should be about 1/32" clearance between the contact points. If the igniter is stuck, proceed to overhaul the igniter as follows. Take the cotter pin and torsion spring off the outside end of the igniter shaft. Remove the nut from the anvil taper pin and remove it. Caution: This is a tapered pin and must be removed from the top. It cannot be driven through. If this pin is very badly worn one can be made from a 1/4" steel bolt with SAE thread and a grinding wheel. Next remove the moveable electrode shaft from the igniter. Take out the stationary electrode and the mica washers. It is advisable to replace the mica washers with new ones. The old ones frequently get enough rust in them to short the igniter out. Be sure to place enough mica washers on each side so that the points will match perfectly when the washers are tightened down. Re-grind the moveable electrode into its seat. Place a small amount of valve grinding compound on the seat of the moveable electrode and grind the seat with an oscillating motion. Grind with a firm, but not heavy pressure. Wash all igniter parts in gasoline and reassemble as it was. Check to see that there is about 1/32" gap in the points when the hammer is pushed up.